Aharen-san Is Indecipherable

The manga was serialized biweekly on Sundays on Shonen Jump+, published by Shueisha under the Jump Comics imprint.

It spans a total of 167 chapters collected in 17 tankōbon volumes released between August 2017 and August 2023.

As of December 2024, the series recorded over 180 million views on Shonen Jump+ and more than 1.4 million copies in circulation.

Author Asato Mizu has called it the work with the biggest public response in their career.

A television anime adaptation by Felix Film aired as a 12-episode first season from April to June 2022, followed by a 12-episode second season, Aharen-san Is Indecipherable season 2, from April to June 2025.

The anime retains the manga’s understated humor and leans into the contrast between extreme deadpan and over-the-top situations.

The manga is based on the author’s earlier self-published doujin work “I Can’t Gauge the Distance Between Us,” whose content is almost identical to the first serialized chapter.

The series is often described as a “low-energy girl everyday comedy” built around Reina Aharen’s peculiar sense of distance.

The story is set at a high school in a rural region far from Tokyo, implied by the fact that characters use airplanes when traveling to the capital.

The exact location is never specified, adding a slightly abstract, anywhere-in-Japan feel.

Reina Aharen is a tiny, soft-spoken girl who is terrible at gauging both physical and emotional distance with others.

Shōta Raidō, a boy who sits next to her, initially feels a quiet wall between them.

One day, Raidō picks up a fallen eraser for Reina, which becomes the catalyst for their relationship.

He discovers her habit of either clinging far too close to people or withdrawing completely because she is afraid of overwhelming them.

Reina tries to distance herself again out of guilt for acting overly familiar, fearing she will repeat past mistakes and end up alone.

However, Raidō calmly accepts her quirks, reassuring her that he does not mind at all, and the two begin spending most of their time together.

From there, their days fill with strange yet gentle episodes: Raidō gets addicted to whatever hobby Reina is currently obsessed with, or he misreads her odd gestures and spins wild mental scenarios.

Classmates, nearby grade-school kids, and family members are gradually pulled into their orbit as the two awkwardly, almost imperceptibly, get closer.

Reina Aharen

Reina Aharen is the main heroine and, in practice, the emotional core of the series.

In the anime she is introduced as a first-year high school student.

She has silver semi-long hair, a very small build, and generally sits in the back-left corner of the classroom staring out the window.

Her face is nearly expressionless and her voice is so quiet that many classmates are not even sure she speaks.

Despite the deadpan exterior, Reina has strong emotions and reacts intensely when pushed.

She is capable of deep shock, anger, and big, streaming tears when she is moved or hurt; she simply struggles to express those feelings outwardly in a readable way.

Reina eats a lot, often consuming a lunch larger than Raidō’s and still looking unbothered.

Her appetite is a running gag and helps contrast her small stature with a surprisingly sturdy constitution.

Among neighborhood children, particularly a boy named Atsushi, she is worshipped as “Lord Ahaoh,” a somewhat misheard, overdramatic title.

Reina herself is plainly bewildered by this cult-like treatment.

Her difficulty lies in “measuring distance”: she either gets uncomfortably close to people physically and socially or withdraws so much that she appears cold.

After Raidō returns her eraser and then accepts her closeness without complaint, she opens up and begins acting more naturally—though her “natural” is still incredibly odd.

Her family name, Aharen, is rare but does exist in Okinawa, and many other characters in the series also have surnames associated with Okinawa.

This detail subtly hints at the author’s background and adds regional flavor to the cast.

Shōta Raidō

Shōta Raidō is the male lead and Reina’s constant partner once the story gets going.

On the surface he is an ordinary high school boy, but his inner world is anything but ordinary.

Most people call him Raidō or Raidō-kun, and his younger sister simply calls him “big brother.”

Reina’s younger brother Ren knows him as “Raidō big brother,” highlighting their quickly formed bond.

Raidō has a powerful tendency toward extreme, elaborate imagination.

Any tiny, ambiguous gesture from Reina can send him into a cascade of worst-case or wildly dramatic scenarios inside his head.

He knows this is a bad habit and will immediately abandon his theories the moment he realizes they are wrong, switching back to a calm, pragmatic mode.

This quick mental pivot turns his delusions into a safe source of comedy rather than cruel misunderstandings.

He is unexpectedly knowledgeable across a wide range of topics, which occasionally makes his wild theories oddly detailed and even useful.

Ironically, he is bad with animals, especially dogs, mentally labeling even friendly ones as “ferocious beasts” and panicking around them.

Raidō’s own face is also quite expressionless, to the point that he and Reina train together to improve their facial expressiveness.

In practice, the difference on the page or screen is almost nil, and the gag is that he never truly “fixes” it.

When he catches a cold, he suddenly fits the proverb “a woman with eye trouble and a man with a cold are strangely attractive.”

In this state, he radiates a languid charm that makes people of every gender around him flustered and nervous.

He sits next to Reina in class, which is how their story begins when he returns her dropped eraser.

He finds her behavior confusing but never truly unpleasant, and his gentle acceptance is the anchor that allows her to stay close.

In the final volume, a special chapter entitled “Raidō-kun Wants to Be Called By His Name” reveals that his given name is Shōta.

This detail cements his full identity after readers have spent most of the series knowing him only as Raidō.

Mitsuki Ōshiro

Mitsuki Ōshiro is Reina’s childhood friend, usually called Ōshiro-san.

She is tall for a girl, with a constant worried expression and a tendency to blush.

As a first-year she is placed in a different class from Reina, but from their second year onward they share the same classroom.

Her height is a serious source of insecurity, especially compared to tiny Reina, whom she has always looked after.

In elementary school, Reina once told Mitsuki that she thought Mitsuki was cute.

Since then, Ichiki becomes painfully shy face-to-face with Reina and for years has preferred watching Reina from a distance in middle and high school.

When she first notices Raidō spending time with Reina, Mitsuki decides he must be a villain seducing her precious friend.

She stalks and confronts him, but once they clear the misunderstanding, she can finally talk normally with both him and Reina.

Her parents are barbers, so she is comfortable cutting hair and also knows how to do makeup and massages.

She has impressive physical strength—she practices boxercise and weight training—and displays high athletic ability, such as cutting rolled straw mats with a single motion or catching a bee with chopsticks.

Her “watching from afar” habit has turned her into an expert at hiding.

She has secret hiding spots all around the classroom, although Reina frequently detects her presence anyway, undercutting her stealth.

Ishikawa

Ishikawa is a good-looking, sociable classmate who is childhood friends with Hanako Satō.

He has high communication skills, plenty of friends, and used to belong to the badminton club, reflecting strong athletic ability.

He casually supports the budding relationship between Reina and Raidō by nudging situations in their favor.

He is one of the people Raidō talks to the most, often acting as the “normal person” reacting to the duo’s strangeness.

Hanako Satō

Hanako Satō is Raidō and Reina’s classmate and Ishikawa’s childhood friend.

She quietly harbors romantic feelings for Ishikawa.

Every now and then, Ishikawa slips and calls her “Hana-chan,” a childhood nickname, but she insists on the more distant “Satō-san” now that they are in high school.

This small struggle over what to call her reflects both her feelings and her desire to appear “ordinary.”

Hanako is obsessed with being “normal.”

She describes herself as a completely ordinary high school girl in an ordinary school who attends normally, participates in a normal club, and lives a normal life.

She and Ishikawa often watch Reina and Raidō’s antics together with a smile, but internally she is baffled by their off-the-wall behavior.

Still, because she wants to be normal and agreeable, she usually suppresses her confusion and avoids showing it openly.

Riku Tamanaha

Riku Tamanaha transfers into Reina and Raidō’s class in their second year, first appearing in chapter 71.

Her style is visually “gal-like”: a loosened uniform, white hair tied with a scrunchie, and sun-kissed skin.

She is cheerful and extroverted on the surface and quickly takes a liking to Reina, dragging her around to various shops.

However, it is revealed that she is actually one of Reina’s elementary-school friends who drifted away in the past.

Reina believed that this breakup was her fault, assuming her inability to gauge distance had driven Riku away.

In reality, Riku herself had felt guilty for constantly dragging Reina around and overwhelming her, so she chose to distance herself.

Once this mutual misunderstanding is resolved, they pick up their friendship again, and Riku returns to calling Reina “Aha-chan.”

Beneath the flashy exterior, Riku is deeply socially anxious and easily interprets neutral comments as negative.

She often misreads reactions, flees from conversations, and hesitates to insert herself into social circles, fitting the stereotype of an extreme communication-phobic person.

Because of frequent transfers during childhood, she cannot initially recognize Mitsuki Ōshiro as a former classmate, highlighting how turbulent her early life was.

Ms. Miyahira

Ms. Miyahira is a physical education teacher and homeroom teacher for Reina and Raidō’s class during their first year.

She has a bright, big-sister-like presence.

She is very close friends with another teacher, Ms. Tōbaru, whom she affectionately calls “Momo-chan.”

Miyahira frequently visits Tōbaru’s home, cooks for her when she is unwell, and even travels with her, making their relationship notably tight-knit.

Ms. Tōbaru

Ms. Tōbaru is a classical Japanese literature teacher and becomes homeroom teacher for Reina and Raidō’s class in their second year.

Her eyes are nearly always closed to slits, giving her a slightly sinister or scheming appearance.

She is close to Ms. Miyahira and develops a fascination with Reina and Raidō’s intimate but awkward dynamic.

She observes their interactions like an aesthetic experience, labeling them with old literary terms such as “pitifully lovely” and “charming,” and often reaches a personal “critical dose of emotional overload.”

Whenever their “cuteness” surpasses her limits, she suffers dramatic physical reactions such as nosebleeds or coughing blood, occasionally interrupting class.

She is also a history and traditional culture enthusiast, well-versed in old Japanese games.

In one scene she plays battledore (a shuttlecock game) against Reina and Raidō and absolutely overwhelms them, despite being alone, in kimono, and facing two students at once.

The only time she loses is when Reina appears dressed in an old-fashioned “revenge raid” costume, which touches Tōbaru so much that she is defeated by her own emotional reaction.

Mr. Heianzan

Mr. Heianzan is an English teacher and becomes the homeroom teacher when Reina and Raidō reach their third year.

He is a new, highly motivated educator with a sharp smile and distinctive fang-like teeth.

He arrives on staff full of passion for proper teaching and guidance.

However, before he can fully settle in, Ms. Tōbaru warns him about Reina and Raidō as “people of dangerous, overwhelming cuteness” that require special handling.

Whenever the students behave in ways he cannot interpret, he frantically consults the official curriculum guidelines to see how to respond.

If there is no clear answer, he collapses into self-blame, lamenting that he is a “failure as a teacher,” showing his dramatic emotional swings.

He appears to have known Ms. Tōbaru from before being assigned to this school, apparently as a junior colleague in some earlier professional context.

The exact nature of their history remains unexplained, leaving room for speculation and humor.

Raidō’s Little Sister

Raidō’s Little Sister is a middle school girl whose first name is never revealed.

She clearly resembles her brother in facial features and shares his tendency toward imaginative overreaction.

Unlike Raidō, her expressions are much more vivid, and she speaks in a curt, blunt manner.

Although she often talks to her brother in a seemingly cold or annoyed tone, she genuinely cares about him.

When she sees Raidō and Reina doing something strange together, she worries that her brother may be getting into trouble.

Once she realizes things are harmless, she relaxes, showing a more typical sibling affection.

She reluctantly helps Raidō practice lip reading, acting as his training partner.

She also gives him a fidget spinner, which becomes part of a small story arc involving neighborhood kids.

She attends the same middle school as Eru Aharen, Reina’s younger sister.

The two girls are friends, creating another point of connection between the two families.

Ren Aharen

Ren Aharen is Reina’s younger brother and an elementary school student.

When Reina is a first-year in high school, Ren is in the fourth grade, making the age gap six school years.

He closely resembles Reina in appearance, to the point that if he wears the same uniform he looks nearly identical.

When Raidō first meets him, he mistakes Ren for Reina the entire time.

However, their personalities are opposites.

Ren speaks loudly, is highly expressive, very social, bad at crane games and video games, and eats only small portions.

He adores both his sister and Raidō, eagerly tagging along whenever possible.

Their trio often participates in weekend activities that magnify the series’ gentle absurdity.

Eru Aharen

Eru Aharen is Reina’s younger sister and a middle school student.

When Reina is in her second year, Eru is in her second year of middle school, making them three grades apart.

Like Ren, Eru’s hair and face resemble Reina’s, but she has sharper eyes, a taller figure, and a notably larger chest.

Her verbal tic is ending sentences with “that’s for sure,” which adds a slightly severe flavor to her speech.

She is terrible at crane games, losing repeatedly despite trying hard.

Eru cares more than anyone about her older sister’s well-being.

She is convinced that Raidō is the most important person in Reina’s life, so she often treats him harshly or suspiciously.

At the same time, she secretly looks out for Reina in countless small ways, deliberately hiding her efforts so Reina will not notice.

Naturally, Reina notices anyway, understanding her sister’s feelings without calling attention to them.

Eru attends the same middle school as Raidō’s Little Sister, and the two are friends.

The school swimsuit Reina uses is a hand-me-down from Eru, humorously labeled an “upward hand-me-down” because the younger sister is bigger.

This detail reflects the series’ willingness to play around with body-type comedy without making it cruel.

Aharen Ai

Aharen Ai is the mother of Reina, Eru, and Ren and visually resembles her children.

She is first shown when she walks into Reina’s room and briefly mistakes Raidō, who is present, for a second Reina figurine.

Her complete lack of surprise reveals that she deeply understands her daughter’s eccentricities.

Ai had already heard a lot about Raidō through Reina and maintains a friendly, relaxed relationship with him.

Her life motto is that “wanting to do something is more important than anything.”

She enthusiastically throws herself into new activities, often ignoring the risk of injury.

Her children constantly worry that she will get hurt because she refuses to back off from what she wants to try.

However, because she herself understands this impulse, she rarely stops her kids from doing things unless something is obviously and seriously dangerous.

Nui

Nui is the large female dog owned by the Aharen family.

She has an astonishing level of intelligence that becomes a running joke.

Nui can bring Reina’s lunch box to school, carefully carry Reina home with the girl lying on her back, and even obey traffic signals.

Atsushi and the other nearby children call her “Lord’s Steed,” as if she were a legendary mount for their “Lord Ahaoh.”

Atsushi

Atsushi is a local grade-school boy who often appears in the neighborhood scenes.

He wears a cap and usually has bandages on his face, emphasizing his hyperactive rough-and-tumble lifestyle.

He first meets Reina in a park while she is quietly spinning a fidget spinner.

Impressed by her aura and skill, he begins calling her “Lord Ahaoh” and treats her like a mysterious boss character.

His childhood friend Futaba has clear romantic feelings for him, but he is completely oblivious.

He frequently brushes her aside in a rough, dismissive way, not realizing how much she cares.

Futaba

Futaba is Atsushi’s childhood friend and another neighborhood grade-schooler.

Her clothing and accessories often feature twin-leaf motifs, visually matching her name.

She has a strong crush on Atsushi but cannot bring herself to be straightforward about it.

Instead, she acts prickly and tsundere, so her true feelings never really get through to him.

At first, she views Reina as a romantic rival, mentally labeling her a “shady older girl with a thing for boys” because Atsushi idolizes Reina.

She even calls Reina a “shota-loving villain” in her thoughts.

Once Futaba realizes that Reina is actually in love with Raidō, her hostility softens considerably.

Her attitude toward the Aharen family becomes more open, and she visits them more often.

Futaba is very good at the board game Reversi, using it to impress others.

By contrast, she is terrible at cooking, with multiple kitchen disasters providing comedic relief.

Takashi

Takashi is a boy with a classic delinquent fashion sense: school uniform, pompadour hairstyle, and tough-guy mannerisms.

At first glance, he looks like a typical teenage punk.

He and his friends once monopolize a mini four-wheel drive race track at the park where Ren plays.

Ren challenges them by bringing Raidō, who proceeds to defeat Takashi in a race.

After losing, Takashi starts revering Raidō as “The Head,” treating him as a sort of neighborhood boss.

However, several clues reveal the punchline: Takashi is actually the same age as Ren and is still an elementary school student.

His height is roughly the same as Raidō’s, and his overuse of katakana-style speech patterns makes him feel like a stereotypical older delinquent.

Despite his scary aesthetics, he strictly follows school rules, further underscoring the gap between appearance and reality.

Production and Broadcast

The television anime adaptation of Aharen-san Is Indecipherable was animated by Felix Film.

Season 1 aired from April 2 to June 18, 2022, in the Animeism B2 block on MBS and TBS, with additional broadcasts on BS-TBS and AT-X and streaming on multiple platforms.

Season 2, titled Aharen-san Is Indecipherable season 2, broadcast from April 7 to June 23, 2025.

It aired on Tokyo MX, BS11, MBS (in the Anime Tokku block), and AT-X, with simultaneous and delayed streaming on services such as ABEMA, U-NEXT, d Anime Store, Hulu, Amazon Prime Video, and others.

Both seasons kept the same key creative staff: original creator Asato Mizu, chief director Yasuhisa Yamamoto, director Tomoe Makino, and series composer Takao Yoshioka.

Character designs were handled by Yūko Yahiro, and animation production remained with Felix Film throughout.

Season 1 featured music by Satoru Kōsaki, Oliver Good, and Keita Inoue.

Season 2’s music was handled by the production group MONACA.

The overall production was overseen by executive producer Kōichirō Natsume, with Ryo Aizawa credited as producer on both seasons.

Each season consists of 12 episodes, for a total of 24.

Voice Cast

Reina Aharen is voiced by Inori Minase, who also voices Reina’s mother, Aharen Ai.

Shōta Raidō is played by Takuma Terashima, with his childhood version voiced by Eriko Matsui.

Mitsuki Ōshiro is voiced by M.A.O (Mao Ichimichi).

Ishikawa is voiced by Tetsuya Kakihara, and Hanako Satō by Tomori Kusunoki.

Riku Tamanaha joins in season 2, voiced by Nao Tōyama.

Ms. Miyahira is played by Yurie Kozakai, and Ms. Tōbaru by Kana Hanazawa.

Mr. Heianzan appears from the third-year storyline onward and is voiced by Iori Saeki.

Raidō’s Little Sister is voiced by Rika Nagae.

Ren Aharen is voiced by Misaki Kuno, and Eru Aharen by Rina Hidaka.

Atsushi is voiced by Natsumi Fujiwara, while Futaba is voiced by Maria Sashide.

Nui the dog shares a voice actor with Raidō, Takuma Terashima, emphasizing the comedic link between them.

This overlapping casting adds an extra meta layer to a number of scenes.

Theme Songs

In season 1, the opening theme is “Hanarenai Kyori,” performed by TrySail.

The song’s lyrics and composition are by KHAi, with arrangement by Yūki Kishida.

The season 1 ending theme is “Kyori-kan,” performed by Hako-niwa Lily.

Its lyrics and composition are by MARUMOCHI BOYS, with arrangement by HoneyWorks.

Episode 3 of season 1 features a special ending song, “Aharen Heart,” sung in-character by Reina Aharen (Inori Minase).

It was written by Kanako Yaginuma and composed and arranged by Satoru Kōsaki.

In season 2, the opening theme is “Binetu Ma,” performed by Zutto Mayonaka de Ii Yo ni.

Lyrics and composition are by ACA-ne, arranged by the team 100kai Outo and ZTMY.

The season 2 ending theme is “Twilight.”

It is written and composed by lia and arranged by Naoki Itai and Yusuke Koshiro.

Episode Structure

Each episode title usually ends with a casual question like “Isn’t it too close?” or “Isn’t this a summer festival?”

This framing fits Raidō’s constant internal questioning of Reina’s behavior.

Season 1 covers early high school life: seat changes, hobbies, dieting attempts, snow days, and a climactic “duel” episode.

Season 2 moves into bigger events such as transfer students, sports festivals, beach trips, a school trip, Christmas, a musical, and the school festival, expanding the cast and emotional stakes.

An original soundtrack album for season 1 was released on June 29, 2022.

It collects the series’ light, whimsical background tracks and character motifs.

Season 1 was released on Blu-ray across three volumes between July and September 2022.

Each volume includes four episodes, along with bonuses such as booklets and clean versions of the opening and ending sequences.

Season 2 was released as a single Blu-ray box set on September 10, 2025.

The box contains all 12 episodes and additional extras, packaged as a single collector’s item.

To promote the anime, an internet radio show titled “TV Anime ‘Aharen-san Is Indecipherable’ Indecipherable Radio” was streamed on the Onsen web radio platform.

It ran weekly from March 31 to June 23, 2022, for a total of 13 episodes.

The show’s hosts were Inori Minase (Reina Aharen) and Takuma Terashima (Shōta Raidō).

They discussed recording stories, answered listener messages, and highlighted favorite scenes from the anime.

Episode 6 (released on May 5) featured guest Mao Ichimichi (M.A.O), the voice of Mitsuki Ōshiro.

Episode 10 (released on June 2) included guest Misaki Kuno, who voices Ren Aharen.

A follow-up program, “TV Anime ‘Aharen-san Is Indecipherable’ Indecipherable Radio 2,” was announced for Onsen and the official YouTube channel.

It was scheduled to begin on March 27, 2025, airing every other Thursday to coincide with season 2’s broadcast.