Nano Eiai

Name: Nano Eiai

Gender: Female

Age: 15

School: Ohana no Mitsu University Affiliated High School, Class 1-4

Year: First-year high school student

Birthday: March 14

Zodiac Sign: Pisces

First manga appearance (chapter info in source text): Volume 2, associated with episode 6 content

Episode where she joins Rentarou Aijou’s “family” (anime reference): Volume 2, associated with episode 7–8 content

Theme BGM: “Nano Eiai.”

Image Song: “Sparkling Forecast” (Seisai Yohou)

Voice Actress (Drama CD): Emiri Suyama

Voice Actress (TV anime): Asami Seto

Self-first-person pronoun in original: “watashi” (standard, polite “I”)

Her birthday is strongly implied to be derived from pi (3.14), and March 14 is officially “Pi Day” and “Mathematics Day”.

It also coincides with Albert Einstein’s birthday and with White Day, any of which could be a deliberate reference for Nano’s character.

Nano Eiai is Rentarou Aijou’s fourth “fated girl” and one of the main heroines.

She is known for her long straight silver hair, red eyes, and tall, slender model-like figure paired with a voluptuous bust.

She wears the blazer-style school uniform like Hahari Hanazono, but with a necktie instead of a ribbon and black tights.

She is roughly the same height as Rentarou, with an elegant figure that still has an E-cup-or-larger chest.

Nano transfers in from Mirene Middle School, just like her senior Mimimi Utsukushisugi.

Back in middle school, she had a bob cut and wore a sailor-style uniform, and that shorter hairstyle is later briefly recreated in-story.

Her academic ability is extraordinary; she constantly ranks first in the year with perfect scores in all subjects.

Because she is so precise, calm, and “mechanical,” rumors circulate that she might secretly be an AI.

Her personality is dry, cool, and highly logical, but also quirky in an “efficiency first” way.

She often prioritizes optimization so strongly that she charges off in bizarre directions that surprise those around her.

Despite her coolness, she is an “efficiently affectionate” type of kuudere once she starts dating Rentarou.

She is willing to skip embarrassment entirely if it would be inefficient, so she can be surprisingly bold.

Nano is a hardcore rationalist who values efficiency above all else.

She once dismissed human relationships themselves as “meaningless inefficiency,” until meeting Rentarou changed her perspective.

Her catchphrases revolve around efficiency, such as “This is more efficient,” or bluntly calling things “meaningless”.

Initially she is emotionally flat and often told she “has no feelings,” but after becoming Rentarou’s girlfriend she shows emotions far more openly.

She used to view fun and “enjoyment” as empty concepts that yield no tangible gains.

Over time, she comes to recognize emotional fulfillment and shared memories as a genuine form of “value” worth pursuing.

Nano is observant, blunt, and extremely straightforward.

She is not cruel; rather, she struggles to see value in anything that doesn’t show immediate, measurable benefit.

She now states that she spends time with the other girlfriends not out of duty as Rentarou’s partner, but because she truly likes them.

Her sense of responsibility and quiet affection show through in the way she looks after others, especially Shizuka Yoshimoto.

Nano’s sense of embarrassment is easily overridden by efficiency.

For example, at the pool she lets Rentarou touch her chest without hesitation if it seems like the most efficient way to achieve a goal.

When under stress or trying to calm herself, she starts reciting digits of pi and can, according to the story, do this indefinitely.

This “pi-chanting” tick resurfaces especially when she is flustered by love-related situations or intense logic breakdowns.

She is skeptical toward non-scientific phenomena like ghosts, angels, or fairy-tale magic.

However, she is open to the “fairy-tale” of human kindness, such as doing good deeds and making others happy.

Nano’s academic results are nearly flawless: she once scored 700/700 (perfect scores in all subjects) and ranked 1st out of 240 students.

Her memory, processing speed, and learning ability are depicted as well beyond normal human levels.

She can memorize extremely long restaurant menus at a glance.

She can also store and recall complex auditory information, such as 21 different drink orders at a yakiniku restaurant, without writing them down.

She performs instantaneous calculations, such as predicting falling trajectories or water-gun travel times, in real time.

Rentarou comments that she is like a walking wiki, saying “What humanity’s smartphones really need isn’t Siri, it’s Nano.”

Nano speaks, reads, and writes English fluently and can also discuss obscure local topics, like biker gangs or a neighboring town’s mayor, from memory.

However, she still has personal opinions—she once argued in the novel that the “Puppis” constellation should be renamed something more “linear” to match its shape.

Her physical abilities are also above average, though still within human limits.

Because she calculates the most efficient way to move, she often appears almost robotic in precision.

Examples of her precision and quick judgment include:

Snatching the nearest “winning” prize from a pile at near-relativistic speed (exaggerated comedic framing).

Flicking a stone with her fingernail through a pet door and turning an inner lock to open a door.

Catching a ball in a glove and instantly throwing it back in one fluid motion.

Swallowing sushi without chewing thanks to a “special-alloy-like” throat (comedic exaggeration).

Singing with perfectly accurate pitch and rhythm.

Reflexively stealing the bat from someone attempting a butt-hit and delivering the counter butt-hit herself.

Drawing straight lines and symmetrical figures freehand.

Studying without moving a single millimeter of posture, like an android.

Running full-speed in a spoon race while keeping the egg perfectly balanced, her right hand not moving at all.

Because of her quick thinking and agility, she can rescue people in moments of crisis.

She saves family members whose spirits temporarily left their bodies and grabs Shizuka when a strong wind blows her away.

She tries to avoid head-on fights with overwhelmingly powerful foes, preferring efficient tactics that minimize damage and fatigue.

Even though she seems “superhuman,” she does experience normal injuries and fatigue, such as a cracked nail from stone-flicking or muscle pain after baseball practice.

Before meeting Rentarou, Nano believed human relationships, fun, and emotional experiences were a waste of time.

She treated love as a biological mechanism leading only to marriage and children, both of which she considered unnecessary during high school.

After becoming part of Rentarou’s “family,” she gradually changes.

She begins to treasure shared memories and keeps a growing collection of mementos in her room.

Items she displays include:

A photo from her first date with Rentarou.

A crocheted moon plushie from Meme Kakure as a “let’s be closer” gift.

A “Butt-Bat-kun” keychain from the “Butt-Batting Center Meitou” batting center.

Handmade clothes she wore when she was shrunk by Kusuri Yakuzen’s medicine, originally given by Meme.

In the novel, Nano initially calls instant cameras “failure devices” because if the photo is lost, the record is gone, unlike digital data.

Later, she quietly buys the same instant camera model that Rentarou uses, showing how much she values their shared experiences.

Her view of people also evolves.

Where she once would have cut people off as inefficient, she now refuses to abandon friends for the sake of “optimization” and acts with genuine kindness.

She still analyzes emotions like a scientist, saying things like “So this is the concept called ‘X’,” but she clearly feels them deeply.

Her actions frequently reveal her care even when her words are overly clinical.

Nano is a very tall, slender girl with waist-length straight silver hair and striking red eyes.

Her figure is described as “model-like,” yet she also has very large breasts (E-cup or more).

She wears the school blazer uniform with a necktie and black tights, giving off a sharp, dignified impression.

Her elegance and cool aura cause rumors that she is “the most beautiful first-year student” in the school.

Students initially talk about her as “probably an AI,” but by around chapter 120 she is more widely known as “the most beautiful first-year.”

Her image color is a pale silver or white reminiscent of snow or blizzards; in goods and art, it is often approximated with soft purple tones.

Despite her beauty and the fact she looks amazing in both feminine clothes and in boyish or “prince” outfits, she personally doesn’t care about aesthetics.

She once stated that going bald would be more efficient because it would eliminate hair-care time.

When asked to show her “true free self” in a fashion sense by Nadeshiko Yamato, she chooses a high-performance racing swimsuit (like a “Laser Racer”) for its functional efficiency.

Although others consider her extremely cool and handsome when cross-dressing (for example, acting as a prince to wake Rentarou), she struggles to understand why.

Nano always calls people by their full names without honorifics.

She even calls Nadeshiko Yamato by her actual Japanese given name “Nadeshiko” rather than her nickname.

This full-name habit is strikingly inefficient on the surface.

One fan theory is that she sticks to full names so she never has to maintain multiple nicknames for people with the same name; another is that she considers a person’s full name part of the “memory” she wants to preserve.

She has several quirks linked to her obsession with efficiency:

She chants digits of pi to regain concentration.

She rejects hot drinks because waiting for them to cool is “inefficient,” preferring lukewarm beverages.

She mostly orders water, viewing juice as an inefficient method of hydration.

She used to replace meals with supplement pills and even put “calorie-mate” type additives into hotpot to optimize nutrition.

Her appetite is extremely small.

She becomes full after about nine pieces of sushi, and simply eating one more sausage than usual in her lunch can make her feel like she might vomit.

Because she once relied heavily on supplements, she treated food purely as fuel.

After bonding with the family, she begins to treat meals together as a form of memory-making and brings more “normal” bento, though she still eats very little.

When “drunk-like” (for example, under the influence of certain conditions), she becomes very touchy and fond of stroking others’ hair.

Her otherwise calm demeanor falls apart and she becomes “petting drunk,” focusing on gentle physical affection.

Her home matches her personality: a minimalist, decoration-free building that screams efficiency.

She appears to live with both parents—there is an anecdote where one of her father’s side dishes accidentally ends up in her bento, and she never suggests her parents are absent.

Notably, her parents allow her to stay overnight at Rentarou’s house when she is shrunk, implying a fairly rational but oddly permissive household.

Given Nano’s own pattern, her parents may share her rationality but also experience “love-induced bugs” in their decision-making.

Nano herself says that she has never experienced “fun” time before high school and avoids talking about her childhood.

Her early years remain largely mysterious, hinting at a possibly lonely or hyper regimented upbringing.

Despite her seemingly perfect abilities, Nano has weaknesses.

The most notable is her fear of heights.

When she is in a high place, like a ferris wheel or a diving platform, she freezes and literally cannot move.

Her body trembles uncontrollably and she becomes unable to function efficiently at all.

In one episode, Rentarou helps her cross a high bridge by noticing her slight trembling and swimming across the river while carrying her.

Her fear of heights makes amusement-park rides like ferris wheels a serious challenge for her.

She also has a lingering discomfort with overtly grotesque or excessively violent scenarios, despite her once-darkly “efficient” suggestions.

Later in the series, she tells Rin Baio that she has “no talent for violence,” although Rin notes that Nano wielding a butt-bat on Iku Sutou looked pretty violent.

Early on, Nano’s efficiency logic leads her to make statements that sound almost like an assassin.

She once quips that “poisoning is more efficient than seppuku,” suggests a specific method for fighting off molesters, and casually mentions that aiming for the carotid artery is effective.

She also routinely carries a box cutter.

She uses it because a blade is an “efficient cutting tool,” but this has led to some unnerving scenes.

For example, she acts out a stabbing to scare Mei Meido into opening her eyes, retracting the blade at the last moment.

At another time, she dual-wields box cutters to slice through the rampaging hair-tentacles of Hahari Hanazono.

As the story progresses, these openly “assassin-esque” habits diminish.

Her comments grow less morbid as her empathy and appreciation of relationships deepen.

Later, she even confides to Rin Baio that she lacks talent for true violence.

Rin, however, points out that Nano enthusiastically performing butt-bat punishments on Iku looked pretty intense.

Rentarou Aijou

Rentarou Aijou is Nano’s destined soulmate and the protagonist of the series.

Nano’s feelings for him initially clash with her logical worldview, causing an internal “efficiency error.”

Their first real encounter happens when Rentarou returns to his classroom to retrieve his smartphone, which he calls “a treasure more precious than life” because it holds photos and memories with the other girls.

He and Nano make eye contact, and the trademark “soulmate reaction” triggers.

Rentarou invites Nano to go see the posted midterm exam rankings together.

Nano refuses, saying it is meaningless because she already knows she will be first and checking would be a waste of time.

Sure enough, she achieves perfect scores and ranks first in the entire year.

Rentarou hears about the rumor that she might secretly be an AI due to her performance.

During a biology experiment, Rentarou pairs with Nano.

Nano refuses to look through the microscope and instead perfectly recreates the textbook’s onion-skin cell diagram from memory, calling the whole experiment a waste of time.

She dryly argues that repeating known experiments has no value when the answers are already established by “predecessors.”

Even when asked to at least pretend to participate, she only looks at the textbook through the microscope as a joke.

When Rentarou accidentally cuts his finger on a razor, Nano immediately takes his hand and sucks the wound, quoting the germ-killing effect of saliva.

Rentarou thanks her and expresses a desire to talk more, but she responds that while she does not dislike him, conversation itself is “meaningless” and “fun” gives no concrete gains.

Despite this, Nano is shaken by her own reaction.

At home, she questions why she licked his wound when she is fully aware of the bacterial risks.

Unable to reconcile her actions with her logic, she fills sheets of A4 paper with digits of pi and tapes them all over her walls and ceiling.

It is an attempt to drown out her feelings with numbers and regain stability.

Eventually, she admits to herself: “I like Rentarou Aijou.”

She goes to him and confesses, asking him to date her.

Rentarou happily accepts, but Nano’s rational brain kicks in.

She claims love only yields “marriage” and “children,” neither of which she needs right now, and concludes that being rejected would be most efficient.

Since Rentarou has accepted her, she decides she must reject him herself, insisting on breaking up immediately after confessing.

To outside observers, her behavior is completely absurd, but internally she is trying to “close the process” with minimal future cost.

However, Rentarou refuses to give up.

He reveals he has already been rejected 100 times in his life and declares that he will not allow this “small” heartbreak to end their love.

He instead proposes a compromise: one date.

If they spend one day together and she still wants to break up, he will accept it.

They go to an amusement park for their first date.

Rentarou tries his best to entertain Nano, using an instant camera to capture their memories.

Nano, however, gives brutally analytical feedback: she questions why the park has a riding machine like a training device, calls a haunted house “just a human house,” and labels a spinning ride a “musical brainwashing device.”

Her comments highlight her inability at that time to engage with pure fun.

On the ferris wheel, her acrophobia surfaces and she trembles.

Rentarou senses her fear and gently takes her hand, and she squeezes back, revealing a softer side.

At the end of the day, Rentarou looks through their photos.

He points out how he can identify subtle differences in her facial expressions—joy, surprise, anxiety—even though people say she is expressionless.

Nano insists the day was “fun” but “brought no gains.”

To prove a point about the value of memories, Rentarou tries to burn the photos.

Nano reflexively snatches them back before they burn.

Rentarou notes that “you can’t lose something you never had,” and that she instinctively tried to protect those memories.

She begins to cry without realizing it.

Rentarou apologizes for the harsh method but explains he wanted her to see that “happy time” itself has value and is a reason to live.

After sorting out her feelings, Nano confesses again.

She tells Rentarou she wants to date him and experience more of these “meaningful” moments together.

Rentarou reaches for a handshake, but Nano pulls him in and kisses him directly.

He blushes at her boldness, and their “efficient” yet deeply emotional relationship truly begins.

Later in the series, Rentarou affirms that he loves Nano in every form.

This includes her physical appearance, which he openly admires, and her signature long silver hair that he says he loves.

Nano tests his devotion by asking if he would still love her if she went bald.

Thanks to his growth and her own understanding of him, she trusts that the answer is yes.

When she is shrunk by Kusuri Yakuzen’s experiment into tiny “One-Inch Nano,” Rentarou builds her a miniature life: a mechanical pencil as a bed, a tiny toilet, and hand-crafted problem sets.

This meticulous care demonstrates his dedication, which Nano deeply appreciates.

In an alternate timeline event (chapter around 209), the world is changed so that Rentarou forgets Nano.

However, because she is still his destined soulmate, he falls for her again, confesses, and re-creates the dynamic of their original date, helping restore the original world.

Nano often teases Rentarou and calls his more insane stunts “the level of absurdity” and warns that if he tried them during surgery she would not come.

In her dreams, she strongly rejects the idea of Rentarou dressing as Shizuka, showing she’s not interested in “cosplay Rentarou” that crosses certain boundaries.

Shizuka Yoshimoto

Shizuka Yoshimoto is Nano’s classmate in 1-4 and her most prominent partner character (they share volume covers and even co-run a bookstore booth).

Shizuka is small, shy, and adorable, which completely short-circuits Nano’s rational brain and awakens a powerful protective instinct.

Nano frequently pats Shizuka’s head, helps her practice flutter-kicking at the pool, and shelters her like a fragile little animal.

She once describes Shizuka as “a creature that will die if someone doesn’t protect it.”

They share a deep bond through books.

Shizuka loves reading, while Nano often sits in the library solving problem sets; they naturally gravitate toward each other as quiet, studious types.

In one chapter, they open a joint “Nanisei Bookstore” booth together.

Their interactions there are filled with Nano’s deadpan comments and Shizuka’s gentle reactions.

During a prank meant to shock Mei Meido—Nano fakes stabbing Mei with a box cutter but retracts the blade at the last second—Shizuka bursts into tears in terror.

Nano is more shaken and panicked than ever before, clearly devastated that she scared Shizuka.

On holidays, Nano and Shizuka go shopping together.

Their outings become more frequent and more intimate over time, hinting at a quietly intense bond.

In a karaoke episode, Nano starts to confess, “Shizuka Yoshimoto, I… about you, I…” before trailing off.

While she doesn’t finish the sentence, the implication is that her feelings for Shizuka are very special.

Later, during a “beauty-spotting” game, when it is Shizuka’s turn, Nano accidentally lists Shizuka’s “cute points” instead of her “beautiful points.”

Her fixation on Shizuka’s cuteness exposes just how much she adores her.

When Shizuka’s mother confiscates Shizuka’s smartphone, Nano is the first to detect Shizuka’s change in behavior.

She works hard behind the scenes to help resolve the situation, showing just how closely she watches over her.

Mimimi Utsukushisugi

Mimimi Utsukushisugi is Nano’s senior from Mirene Middle School.

They share a past in which Mimimi once extended a hand of friendship that Nano, then a pure rationalist, rejected as “meaningless.”

Nano deeply regrets that rejection.

As a form of atonement, she deliberately accepts Mimimi’s challenge to a “beauty-spotting” contest and uses it as a path toward reconciliation.

Mimimi sees Nano as an embodiment of “beauty.”

For Mimimi, “cute Nano” is a kind of canon-breaking contradiction, and she panics whenever she feels Nano is acting in a way that might “spoil” her beauty.

When Nano takes initiative—like holding Mimimi’s hand or closing physical distance—Mimimi’s nerves spike and her composure collapses.

She stammers, shakes, and her movements become shaky and imprecise.

Through their contest and subsequent interactions, Nano and Mimimi eventually reconcile.

Nano now respects the emotional richness Mimimi values, while Mimimi accepts Nano’s growth and newfound appreciation for connection.

Mei Meido

Mei Meido is a fellow “robotic” character whose life revolves around a master-servant dynamic.

Nano, herself often called robot-like, once describes Mei as “like an android.”

In a water-gun-themed “wet maid party,” Nano and Mei fight an incredibly high-level duel.

Their combat is so intense that Shizuka comments that “that corner looks like a completely different series.”

Both Nano and Mei admire Momoha Bonnouji (Hyappachi Bonnouji), a woman who lives almost purely by desire and fun.

Each of them hopes to someday live as freely as Momoha, though Momoha herself yells at them not to follow her “hopeless” example.

Meme Kakure

Meme Kakure is Nano’s classmate and fellow girlfriend, as well as the creator of many amigurumi (crocheted dolls).

When Nano is shrunk by Kusuri Yakuzen’s medicine, Meme lends her tiny clothes, later inspiring Nano’s own crafting attempts.

Nano tries to knit amigurumi herself and produces dolls with factory-level uniform perfection.

However, she feels they lack the warmth of Meme’s hand-made dolls.

Meme suggests that Nano hold the doll every day while thinking about the person she’s making it for.

Following this advice, Nano’s amigurumi become softer and more “lived-in.”

After several days, she finishes a floppy, cuddly doll and gives it to Meme as thanks for the clothes she used while tiny.

Meme is deeply moved, having assumed Nano was making it for Rentarou instead, and blushes in embarrassment while thanking her.

Suu Hifumi

Suu Hifumi is a girl who loves numbers for their own sake.

Nano’s infinite recitation of pi excites Suu, who watches with sparkling eyes as Nano rattles off digits.

Rin Baio comments, “Will Nano run out first, or will Suu get bored first?”

Shizuka dryly notes that the most likely outcome is simply that “this chapter will end first.”

Nano uses numbers as tools: for calculation, optimization, and prediction.

Suu, by contrast, loves numbers as entities in themselves, almost religiously.

This creates an interesting contrast between them.

Nano is perhaps the ultimate “utilitarian of numbers,” while Suu is the pure “number romantic.”

Kusuri Yakuzen

Kusuri Yakuzen is the mad-scientist-style genius who shrinks Nano with a “smallification” drug.

During this time, Nano becomes “One-Inch Nano” and has to navigate the world at a miniature scale.

Nano sees the efficiency in having Kusuri’s tech as a tool, but Kusuri’s chaotic experimentation clashes with her desire for predictable results.

Despite this, Nano collaborates with Kusuri’s inventions on several occasions, especially in alternate or novel stories.

Kusuri’s father, Yaku Yakuzen, appears in separate contexts, but Nano mostly interacts with Kusuri herself.

Nano’s tiny adventure at Rentarou’s house, aided by Kusuri’s drug, becomes one of her most unique experiences.

Other Family Members and Friends

Nano interacts with many other girlfriends and side characters in the series:

Hahari Hanazono and Hahari’s Father: Hahari’s rampant “hair-tentacle” episodes are sometimes handled by Nano with swift box-cutter interventions.

Kurumi Haraga: Another classmate in 1-4, often present in group scenes where Nano provides deadpan commentary.

Iku Sutou: The primary target of the notorious butt-bat punishments; Nano’s reversal of the bat strike on Iku becomes legendary.

Rin Baio: A delinquent-type character with whom Nano discusses her lack of true “violence talent.”

Kishika Torotoro: Comments on the pi-recitation battle between Nano and Suu Hifumi.

Matsuri Dei, Meru Zetsubouda, Shiina Usami, Yamame Yasashiki, Eira Kaho, Chiyo Iin, Terano Sauruko, Uto Nakaji, Tama Nekonari, and others: Nano occasionally intersects with this large extended cast as commentator, strategist, or the only one willing to say, “None of this makes sense.”

Even with strangers or non-family classmates, Nano’s reputation has shifted.

Previously feared as an unfeeling AI, she is now admired as the most beautiful first-year, and she even offers fanservice gestures like posing for photos with peace signs.

Parallel-World Nano

In one storyline, a future Nano from a parallel world appears.

This version of Nano comes from a world where she is not Rentarou’s soulmate—or where no soulmates were assigned at all.

Having spent about 20 years honing her technology, this future Nano acquires multiverse travel capabilities.

She explores other worlds seeking higher levels of civilization, only to realize that her own world is the most advanced.

To raise other worlds up to her world’s level, she decides it is efficient to “upgrade” each world’s Nano Eiai.

Her method is to remove those Nanos from social ties and force them into maximum study efficiency.

When she explains this plan to the present Nano, present Nano is horrified and objects.

However, after laying out her cold, logical rationale, future Nano departs to visit yet another world’s version of herself.

This alternate Nano represents a dark path Nano could have taken if she had never met Rentarou and never learned the value of relationships.

It underscores how crucial her emotional growth is to her identity.

Nano 2 (Alien Symbiote)

In the novel side stories, Nano 2 is an alien creature that appears when Rentarou, Hahari Hanazono, and Karane Inda share a “UFO-summoning” triple kiss on the school rooftop.

Nano 2 resembles a classic parasitic alien (similar to certain tentacled sci-fi creatures) and arrives in a UFO separate from the alien encountered by Yamame Yasashiki in another event.

Nano 2’s homeworld has depleted its energy resources.

To survive, they developed technology that converts mental energy into usable power.

On Earth, Nano 2 discovers the massive “love energy” generated by Rentarou’s many passionate kisses with his girlfriends.

Because Nano 2’s species reproduces asexually, they cannot generate their own love energy, making Rentarou’s family’s affection especially valuable.

Nano allows Nano 2 to symbiotically inhabit her body by entering through her ear.

She rationalizes that this is efficient, because while Nano 2 controls her body her own consciousness can rest and they still share sensory data.

Nano 2 periodically returns to its mother planet to deliver this stored love energy, helping to stabilize its civilization.

In between, it sometimes pilots Nano’s body for efficient multitasking, acting like an “auto-pilot” while Nano mentally sleeps.

Nano 3 (Alien Engineer)

Nano 3 is another alien called by Nano 2 from the same homeworld, an engineer specializing in advanced technology.

Nano 3 inhabits Nano from her other ear, creating a double symbiosis.

Nano 3 provides the technical knowledge needed to construct a gigantic “Rentarou Robot” used to fight against a giantified Vice Principal, Anzu Baba.

This turns Nano into the central hub for a comically epic mecha battle.

These novel events are described as “parallel festival” stories that may or may not be canonical to the main manga timeline.

However, they play directly on Nano’s AI-like image by literally turning her into a sort of multi-core, multi-occupant body for alien engineers.

Nano is staunchly grounded in science and rationality.

She rejects the existence of ghosts, angels, and other supernatural beings as “incomprehensible.”

In the world of *The 100 Girlfriends*, however, gods and ghosts do actually exist, making Nano’s skepticism ironically misplaced.

She frequently comments on how certain events lack “reality” or logical plausibility.

In Meru Zetsubouda’s fairy-tale-style stories, Nano and Mei Meido initially show little interest.

For example, when statues without brains come to life in the tale, Nano calls it physically impossible.

However, Meru’s “human-level” fairy tale—that doing good for others brings happiness to both giver and receiver—does resonate with Nano.

She is not against wonder or kindness; she simply cannot accept physically impossible beings.

This nuanced stance means she can appreciate metaphorical “magic” (kindness, trust, love) while rejecting literal magic.

Her own life becomes proof that intangible, “inefficient” things can have real, meaningful impact.

Nano’s name appears to be inspired by the idea of “AI” and “nanotechnology.”

Her initials “N.E.” are sometimes misprinted as “N.A.” in early publications, a minor editorial error corrected in collected volumes.

Her surname is pronounced with stress similar to the Japanese word for “Ochiai” (a rising-falling pattern), not like the English letters “A.I.”.

This detail matters mainly for voice acting and pronunciation guides.

She frequently strikes a peace-sign pose in photos as her “memory-creation pose.”

This small affectation shows how thoroughly she has embraced the idea that memories themselves are valuable data.

Originally, her rumor reputation was dominated by “Is she secretly an AI?”

Over time, both in-story characters and readers come to see her as “the most beautiful first-year” whose heart is just as compelling as her mind.