Sergeant Major Kururu

Kururu is the yellow-colored tactical specialist of the Keroro Platoon.

He is brilliant, inventive, sarcastic, and notoriously unpleasant by his own admission.

He was once promoted at an unprecedented speed to the rank of Major.

However, after manipulating military information for mischief, he earned the resentment of high command and was demoted to Sergeant Major.

Although his rank is technically higher than Sgt. Frog’s, he is not the platoon leader.

Because of his personality and because Sgt. Frog was judged more suitable for command, Sgt. Frog remains the unit’s leader.

Kururu is known for his spiral motif, seen on both his hat and stomach.

He also wears thick spiral-lensed glasses, one of his most recognizable features.

His signature laugh is often rendered as a sinister chuckle.

He frequently speaks with a mocking, theatrical tone and enjoys making others uncomfortable.

Name: Sergeant Major Kururu

Gender: Male

Age: Over 6,000 years old, approximately 20 in Earth terms.

Height: 55.5 cm.

Weight: 5.555 kg.

Rank: Sergeant Major.

Role: Operations and communications strategist, mechanic, inventor, hacker.

Body color: Yellow.

Partner: 623 in the manga, Saburo in the anime.

Voice actor: Takehito Koyasu.

Hobbies: Harassment, cooking curry, curry baths.

Special skills: Inventing, hacking.

Likes: Curry, and borscht in the anime version.

Dislikes: Aki Hinata, Angol Mois, and sukiyaki in the anime version.

Motto: His trademark sinister chuckle.

Kururu first appeared in manga chapter 25 and anime episode 9.

He was initially introduced as the mysterious figure who had given special abilities to 623, later known in the anime as Saburo.

His entrance was memorable.

He appeared suddenly through a strange pen drawn by 623, which was later revealed to be the Materialization Pen.

The details of his first meeting with 623 or Saburo differ between manga and anime.

In both versions, their connection involved a car chase and the Materialization Pen, and the event led the two to become close.

Kururu usually stays in his private laboratory inside the hidden base beneath the Hinata household.

There he tinkers with electronic devices, gathers information, develops inventions, and leisurely enjoys curry.

He often acts independently rather than joining the rest of the platoon.

Even so, inspections of the unit show that his work contributes measurable invasion results in data form.

He handles the platoon’s information processing and mechanical development.

Most of the squad’s machines, invasion devices, and support tools are products of his design.

His technical range is extraordinary.

He can work not only in mechanics and computing, but also in biotechnology, as shown by inventions such as assassin soybeans and the space flower project.

According to the anime, he can even create devices on a planetary scale.

One example is a machine that can slow the flow of time across an entire planet to an extreme degree, though he avoided stopping time completely because communication would become impossible.

In the manga, he was even awarded a five-star evaluation by Black Star.

That recognition suggests that even his strangest inventions have real value when used properly.

Kururu is one of the most capable inventors in the series.

Many of his devices look ridiculous at first, but often prove alarmingly effective.

At the same time, he has a habit of adding unnecessary flourishes and personal obsessions to his inventions.

That tendency often causes plans to fail even when the core technology is excellent.

For example, one of his patrol machines attacked Sgt. Frog and Private Second Class Tamama as well as the target.

Another energy-based invention became too difficult even for Kururu himself to control.

His talent does have limits.

He cannot easily duplicate the Keron Star or repair the Kero Ball without investing major time and effort.

He also seems unable, or unwilling, to build a time machine.

That may be because he understands the danger of tampering with time and treats the subject far more seriously than usual.

When Sgt. Frog and the others were accidentally sent into the past in the anime, Kururu quickly grasped the situation.

He warned them in a very serious tone never to meet their past selves or interfere with the era.

Kururu is openly described, by himself and others, as a nasty person.

He is sly, gloomy, unpleasant, twisted, and enjoys playing the role of the villain.

He is one of the series’ greatest sources of chaos.

Many incidents are blamed on Sgt. Frog, Tamama, and Kururu together, but Kururu often stands out as the worst instigator.

What makes him especially dangerous is that he finds trouble entertaining.

He treats accidents, disruption, and psychological warfare as part of the fun.

He has a personal code about how to be unpleasant properly.

He prefers to appear defeated, then overturn the whole game at the last second.

He also believes in waiting until an opponent feels secure before dropping them into despair.

If someone wrongs him, he prefers to repay it with the most irritating retaliation at exactly the right moment.

For all that, he is not simply cruel.

He can become serious in a crisis, work selflessly for the sake of the platoon, or take on the role of villain to protect someone else.

This hidden sense of loyalty gives him an unexpectedly cool side.

In the anime, Karara even fell for that side of him and briefly began imitating him perfectly.

He also has clear moral lines.

He reacts with disgust to forbidden weapons such as those associated with the ancient Keronian military.

Kururu is physically weak compared with the more combat-oriented members of the platoon.

He dislikes direct fighting, especially hand-to-hand combat, and usually avoids the front line.

His poor eyesight is another weakness.

When his glasses are lost or broken, he becomes visibly rattled.

He is also extremely vulnerable to catastrophic data loss.

Even though he takes precautions, an unexpected event such as a lightning strike can mentally devastate him if it destroys his work.

Despite his intelligence, he can be quick to give up when he calculates that a situation is unwinnable.

If an enemy is beyond the power of either himself or the platoon, he may immediately conclude that resistance is futile.

This is less cowardice than ruthless realism.

In those cases, the enemy is usually so overwhelming that brute force would not have worked anyway.

Some aspects of Kururu vary between the manga and anime.

In the manga he is shown as being strong with alcohol and somewhat small-eating.

In the anime, he often appears to be a hearty eater.

He enthusiastically devours not only curry and borscht, but also foods such as watermelon.

The anime also exaggerates some of his more extreme behavior.

At times he is shown building dangerous systems such as a powered suit programmed to go berserk against Keronians.

Another notable anime-specific trait is his voice performance.

Because Takehito Koyasu is famous for handsome and composed roles, Kururu’s “serious mode” shifts dramatically in tone.

Normally his voice is rough, strange, or theatrically sinister.

When he becomes intensely focused and calm, his voice turns smooth and sharp, and he drops many of his usual verbal quirks.

In these moments, he often isolates himself in a deep underground computer room connected to his laboratory.

That presentation highlights how dangerous he becomes when he stops playing around.

His official emoticon in correspondence with Mutsumi or Saburo is also established in supplementary material.

It is represented as a face with a sharp, mocking expression.

Kururu is strongly associated with curry, especially in the anime.

He is shown enjoying curry baths and treating curry as one of his greatest pleasures.

In the manga, however, this obsession develops more gradually.

Early references only lightly mention him being absorbed in making curry.

A later story suggests that his interest in curry was triggered by a mysterious communicator who manipulated him into becoming fascinated with it.

Kururu was impressed enough by that person’s skill at provocation to call them an even worse person than himself.

Even then, he tried to dismiss curry as trivial.

Still, his behavior elsewhere shows that he took it seriously enough to be rattled when his curry was called fake.

His curry-making skill is said to be highly advanced and completely systematized through theory and numbers.

In one story, a professional chef from the Nishizawa household tasted Kururu’s retort curry, left behind a note saying he would start over, and disappeared in shock.

Sgt. Frog

Kururu is especially close to Sgt. Frog.

In the manga’s relationship charts, their bond is described as that of dangerous bad friends.

He often customizes machines to match Sgt. Frog’s tastes.

He has also helped him in practical ways, such as arranging for him to make it to the launch for the Earth invasion when he was running late.

When Natsumi Hinata searched for a lost Sgt. Frog, Kururu was the only one who truly helped.

When Sgt. Frog once fell ill, Kururu insisted he was not the medical officer, but was visibly worried when Sgt. Frog still placed his trust in him.

Corporal Giroro

Kururu and Corporal Giroro have a poor relationship.

The manga labels them as being on very bad terms, and Kururu often teases him for amusement.

Kururu does still refer to him as a senior.

However, Giroro’s strict military attitude clashes hard with Kururu’s cynicism and unserious manner.

In practice, the hostility often feels more one-sided from Giroro.

Even so, Kururu clearly sees both Sgt. Frog and Giroro as burdened by their own inefficiencies.

Angol Mois

Kururu has a degree of discomfort around Angol Mois, similar to the unease he feels around Aki Hinata.

Yet in operations and emergencies, he works with her extremely well.

He often supports her from behind the scenes and handles operator duties when needed.

When Mois was sealed away by her own stress and impulses, Kururu responded with full effort, hinting at a special concern for her.

623 and Saburo

Kururu’s partner is 623 in the manga and Saburo in the anime.

This relationship is one of the most distinctive in his characterization.

Their bond begins with mystery, competition, and shared fascination with unusual technology.

They later become close enough to be remembered by fans as a duo linked by strange signals and odd genius.

Winter Hinata

Among Earthlings other than his partner, Kururu gets along relatively well with Fuyuki Hinata.

Their shared indoor temperament helps them connect.

He has sold Fuyuki materials about Easter Island and, in the anime, often appears alongside him.

This makes Fuyuki one of the few humans with whom Kururu seems comparatively relaxed.

Aki Hinata

Kururu is uneasy around Aki Hinata.

At the same time, he secretly shows an odd fascination with her, including voyeuristic behavior and the creation of a body pillow in her likeness.

New Keroro

Kururu shows some interest in New Keroro.

However, he dislikes being called “Professor” by him and becomes irritated when New Keroro refuses to use the Kururu-style methods he prefers.

Tororo

Before the Garuru Platoon invasion, Kururu and Tororo had already crossed paths as hackers.

Tororo repeatedly attempted to infiltrate the Keronian military’s main server, only for Kururu to crush every attempt.

Kururu later remembers him dismissively as a brat who desperately kept attacking.

The experience was traumatic enough that Tororo came to fear him.

Kururu also reveals that Tororo’s hacking tools are modified versions of something Kururu himself made casually as a child.

Since the original was his own work and Tororo only made it worse, Tororo never truly had a chance in a direct hacking contest.

Inside the story, Kururu is often treated as unpopular.

A wholesaler dealing in Keroro Platoon merchandise once joked that every color except yellow had sold out, implying that his goods were left behind.

In the manga, Kururu seems largely unconcerned with his lack of popularity.

In the anime, however, he becomes visibly depressed when he receives a postcard bluntly saying that someone hates him.

In real life, his popularity is much stronger.

He placed third in a 2009 popularity poll for Keronian-type aliens.

In the official 2010 character poll for Sgt. Frog, his placement gradually slid from first to third, then third again, then fourth, then sixth.

Much later, in the 2021 character election run by the franchise channel, he rose again to second place with 577 votes, only 97 behind first place.

In the anime, Kururu uses a distinctive method to erase memories when the true identities of 623 or the Keronians are exposed.

He emits unpleasant brain-affecting waves through his headphones.

The strength of the signal determines how much memory is lost.

At maximum output, a person can lose one or two years of memories.

A fake toy version of the headphones also appears in a later episode.

That imitation has a time limit, after which the erased memories return.

Kururu is responsible for most of the platoon’s gadgets, inventions, and invasion tools.

His creations usually carry his trademark spiral emblem.

His laboratory brand is also known as Kururu’s Lab.

Many of his invention names reference song titles or lyrics, especially from older music.

Materialization Pen

The Materialization Pen is the mysterious pen Kururu gave to Mutsumi or Saburo.

Anything drawn with it can be made real.

In the manga, its reading is specifically given as Material Pen.

It uses a stone called Koredonite as its raw material.

The method by which Kururu handed it over differs between manga and anime.

Either way, it is central to his earliest connection with 623 or Saburo.

Dream Growth Promotion Gun

This gun can make the target physically younger.

The target keeps their memories, but their personality and behavior shift to match the new age.

It can also undo bodily anomalies such as temporary sex changes.

Clothing may or may not change with the body depending on the story.

New Dream Growth Promotion Gun

This is the opposite of the earlier gun.

Instead of de-aging the target, it physically matures them.

Its design differs slightly, especially at the sight near the barrel.

One version has a flat front while the newer one is pointed.

Earth Animal Soldier Transformation Gun

This weapon transforms animals into humanoid versions of themselves.

Their abilities and personalities are based on their species and original traits.

In the anime, the weapon has a different subtitle.

Kururu himself notes in the manga that it is a defective weapon for military use because its duration and cancellation conditions are unclear.

A reverse version also appears later.

That variant turns humans into animals, but Natsumi Hinata confiscates it.

Weather Satellite Weapon Enmawari

This is a weather-control satellite.

Kururu planned to use it to alter Earth’s climate in ways favorable for invasion.

The manga uses it less often than the anime.

In the anime, one optional system attached to it can make spoken lies come true, giving it wildly abnormal power.

Even so, it does not seem capable of directly changing a person’s heart.

Its power is immense, but not absolute.

Defensive Powered Suit for Natsumi Hinata

This powered suit was developed by the Keroro Platoon together.

Kururu contributed the mobility systems, Sgt. Frog handled the weapons, and Giroro designed the defenses.

Giroro gave it to Natsumi Hinata as an emergency measure.

It later became a regular feature in her battle scenes after the Garuru Platoon’s attack.

When stored, it usually takes the form of a red button with a skull mark.

In its first anime appearance, however, it was instead a choker-like device.

That early anime version could react to words such as attack or battle, including homophones.

It could also forcibly transform Natsumi when her emotions became too intense.

A spare version later appears in the manga and is used by Aki Hinata.

This variant resembles the original but bears Kururu-like markings and appears to improve eyesight as well.

In Sgt. Frog RPG: The Knight, the Warrior, and the Legendary Pirate, Kururu mainly serves as the team’s explanation specialist.

He provides detailed enemy information and useful guidance to the player.

In the manga and anime, that explanatory role is often associated with Giroro.

In the game, Kururu takes it over almost entirely.

Because of this, many players considered him highly useful.

He reveals enemy weaknesses, points out dungeon solutions, and often identifies the path to solving a problem faster than anyone else.

Gameplay Style

Kururu functions as a sage-like magic user.

His weapon category is described as magnetic disks.

His starting equipment includes a record.

His code name is Sergeant Major, and one of his techniques is Microwave.

His field advantage is that hidden items in town become visible.

His drawback is that he moves a little more slowly on the world map.

He is especially effective as a support and healing unit.

He excels at buffing allies and using strong magic attacks against all enemies.

Compared with the others, he has relatively few special techniques and finishing moves.

However, he can use attack magic of every element and can learn all three major recovery types: HP restoration, status recovery, and revival.

He can also reinforce his own stats for self-protection.

This makes him one of the most reliable recovery characters in the party.

His main weakness is low HP.

His attack, defense, and speed are average, but his survivability depends on proper healing support.

Traits

One of his traits increases critical hit rate when striking an enemy’s elemental weakness.

Another makes analysis tools reveal more detailed data.

A third trait shortens his spellcasting time by 30 percent.

This further supports his role as a fast and flexible support caster.

Ultimate Technique

His ultimate move creates the so-called Kururu space-time field.

Its effect is random across five possible outcomes, but it mainly benefits allies through healing or support.

It does not include harmful side effects.

Because of that, it is a strong ability to use often once unlocked.

Computer-Controlled Behavior

When controlled by the computer with a general-purpose setting, Kururu behaves somewhat defensively.

He may steal items from enemies or occasionally provoke them.

If set to support behavior, he generally uses spells appropriately.

That makes him dependable even under automated control.

Card Data

Multiple Kururu cards appear in the game’s card system.

Each has different statistics, hand types, turn speed, and critical values.

One version has 480 HP, a rock attribute, attack power from 80 to 129, a one-turn speed, a 23 percent critical rate, and 235 percent critical damage.

Another has 460 HP, a scissors attribute, attack power from 80 to 129, a one-turn speed, a 20 percent critical rate, and 220 percent critical damage.

A hidden third card can be obtained through the Keparou map.

It has 450 HP, a rock attribute, attack power from 70 to 89, a one-turn speed, a 30 percent critical rate, and 225 percent critical damage.

Kururu is famous in the anime for ad-libbed lines.

Among the Keroro Platoon voice cast, he is often considered the character with the most improvisation.

This is largely due to Takehito Koyasu’s playful performance style.

Some viewers even treated spotting Kururu’s improvised lines in each episode as a game.

These ad-libs are especially common in scenes where he is blasted away or his glasses crack.

His “curry song” is one of the most famous examples.

Even Sgt. Frog’s well-known phrase “Gero-gero-ri” was influenced by this environment of improvisation.

It began as an ad-lib and was later carried back into the source material.