Characters: Sgt. Frog

The cast of Sgt. Frog:
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    The Keroro Platoon 

Sergeant Keroro

Voiced by: Kumiko Watanabe (Japanese), Todd Haberkorn (English) and Eba Ojanguren (Spanish)

"Our hero", a rather hapless Alien Invader who spends more time doing chores and goofing off than he spends actually trying to invade. His plans usually take the form of Zany Schemes that blow up in his face in various amusing ways.

  • Adorkable: In moments when he's genuinely excited about something, he expresses a child-like enthusiasm that is just too cute for words.
  • Anti-Hero: The loser type, most of the time.
  • Bullying a Dragon: His relationship with Natsumi in a nutshell.
    • Becomes a literal example when Warrior-Style was introduced in the manga.
  • Crouching Moron, Hidden Badass: Rarely — very rarely — shows signs of this. In Volume 17, he stops Zoruru dead with a single shadow-wreathed look and a stern order. Then he does the same thing to a Kiruru unit in Volume 20.
    • He also kicks a lot of ass in the movies. Notable examples include: him being turned into a dragon in the fourth movie and proceeding to kick his entire platoon's dragon asses. Note that when he transformed, Keroro, like the rest of his platoon, forgot all about his mission and who he was and while the audience were privy to the other platoon-turned-dragon members thoughts, we do not hear Keroro's at all.
    • In the third movie, Keroro engages his evil clone in a mecha duel to protect Fuyuki and holds on his own fairly well before he was downed. After reuniting with Fuyuki and finding Dark Keroro still alive, he angrily runs over and slaps the clone hard enough to send him flying.
  • Explosive Overclocking: Occurs if he manages to get oversaturated with water, briefly unlocking the Keroro From Back Then before he's brutally Brought Down to Normal again.
  • Idiot Hero: Whenever he and his platoon are charged with saving Pekopon from other alien threats and not being the "threat" themselves.
  • Informed Ability: Supposedly a decorated war veteran, but (almost) never shows any of the competence and bravery you'd expect. A manga chapter eventually explaines why: Just before his first assignment, powerful aliens attacked and were obliterating Keron's forces. Keroro, unaware of all this, uses a port-a-potty which transforms into a space ship, takes off and single-handedly defeats the enemy, then lands. Completely oblivious to what just happened, he steps out to a hero's welcome and promotion to command of his squad.
  • Improbable Weapon User: In many video games, he draws from his collection of toys and cleaning supplies to help him out—the vacuum is a particular favorite.
  • Jerkass/Jerk with a Heart of Gold: Wavers back and forth.
  • Loser Protagonist
  • Man Child
  • The Neidermeyer: While everyone admits he's incompetent, only Giroro openly hates him.
  • Otaku: Of the Gundam variety but also obsesses over the Admiral Geroro manga, space bikes, and trains, surprisingly enough.
  • Trademark Favorite Food: The Funimation dub exaggerates his love of hamburgers (or "cow flesh").
  • Transformation Trinket: The Keron Star, which lets him transform into a pre-peace treaty weapon called Warrior Style.
  • Verbal Tic: Frequently ends his sentences with " arimasu!"
  • Villain Protagonist: Largely a Harmless Villain, of course.
  • Weaksauce Weakness: Banana peels. He's compelled to step and slip on them.

Private Tamama

Voiced by: Etsuko Kozakura (Japanese), Brina Palencia (English) and Pilar Ferrero (Spanish)

The team's youngest member, made obvious by the fact he's still got tadpole features. Despite his cuteness, he's got a hair-trigger temper, a massive jealous streak, and likes firing his laser when provoked. Also, he loves his "Gunsou-san!"

Corporal Giroro

Voiced by: Joji Nakata (Japanese), Christopher Sabat (English) and Víctor Prieto (Spanish)

Keroro's Lancer. Suspects that he's the only one actually taking the invasion seriously anymore. Hopelessly crushing on Natsumi ever since she beat him up during their first fight.

Sergeant Major Kururu

Voiced by: Takehito Koyasu (Japanese), Chuck Huber (English) and Juan Martín Goirizelaia (Spanish)

The team's intelligence officer. Incredibly smug and self-satisfied, Kururu is constantly inventing all sorts of weird stuff, but few of these are actually meant to help the invasion... they're just for his own amusement. Loves giving Keroro just enough rope to hang himself, over and over and over again.

Lance Corporal Dororo, nee Zeroro

Voiced by: Takeshi Kusao (Japanese), J. Michael Tatum (English) and Alberto Escobal García (Spanish)

The team's token Ninja. Used to be a painfully shy, sickly child, and so clung rather desperately to his friendship with Keroro... something Keroro shamelessly exploited, leaving him traumatized to the point that any reminder of these abuses triggers his 'Trauma Switch' and sends him into the nearest corner. Grew up to become an assassin, then got separated from the others on Earth and found acceptance and peace with a group of ninjas, leading to him changing his name and outlook on life.

(Shin) Keroro/New Keroro/Keroro-2

Voiced by: Aoi Yuki

The youngest member and the sole member of the second Keroro platoon. Excitable and naive newcomer. Also the sole soldier within the Keron Army after 100 years.

    The Hinatas 

Fuyuki Hinata

Voiced by: Tomoko Kawakami (Japanese [Eps. 1-231]), Houko Kuwashima (Japanese [Ep. 232 onwards]), Leah Clark (English) and Josu Cubero (Spanish)

A timid Nice Guy who loves the occult. Very introverted, but he's compassionate and polite, and very inquisitive about the world at its weirdest.

Natsumi Hinata

Voiced by: Chiwa Saito (Japanese), Cherami Leigh (English) and Alazne Erdozia (Spanish)

Fuyuki's tomboyish older sister, she considers herself—correctly—to be the first line of defense against Keroro's taking over the planet. Has a massive crush on Mutsumi, and is good friends with Koyuki.

  • Action Girl: The platoon unilaterally considers her Earth's greatest warrior.
  • All Love Is Unrequited: Hopelessly crushes on Mutsumi, while getting crushed on by Giroro, Koyuki, several of her female classmates...
  • Anti-Hero: She's technically on the side of good by protecting the Earth, even if she's a violent, anti-social brute.
  • Badass Normal: She beat Giroro's web of booby traps armed with nothing but a stalk of leek during their first encounter.
  • Defrosting Ice Queen: She may still be suspicious of the Keronians in general, but she also seems to become a bit of a nicer character after they arrive—in addition to Giroro, she gets on pretty well with Koyuki.
  • Even the Girls Want Her: Has a considerable all-female fanclub at school.
  • Girlish Pigtails
  • Good Is Not Nice: She's not the nicest person around, but she is the one keeping Earth from being conquered on an almost weekly basis.
    • She does later admit that she enjoys beating Keroro in particular for no reason.
  • Improbable Weapon User
  • Jerkass/Jerk with a Heart of Gold: Wavers between back and forth, although the former is her more common side.
  • Knuckle Cracking: When those knuckles start cracking, a beating is about to ensue on Keroro.
  • Hidden Eyes: A sure sign of trouble brewing for Keroro.
  • Powered Armor: Her Powered 723 suit.
  • Not So Different: She can be just as arrogant, self-absorbed and overconfident as Keroro at times, which is probably why they get along well.
    • Moreover, she can be as violent, domineering, and no-nonsense as Giroro, which probably is part of the reason he respects her so much.
  • Red Baron: According to Fuyuki in the manga, her overprotective streak during elementary school earned her the nickname Devil Summer.
  • Shorttank
  • Sibling Yin-Yang
  • Tomboy
  • Trademark Favorite Food: Seems to be sweet-potatoes.
  • Tsundere: A vicious Type A on par with the likes of Louise.
  • Waif-Fu
  • Wardrobe Malfunction: Every spin with Kururu's age-ray in the manga ends with her being half(Or totally) naked one way or the other.

Aki Hinata

Voiced by: Akiko Hiramatsu (Japanese), Jamie Marchi (English) and Ana Begoña Eguileor (Spanish)

A famous manga editor. Very self-confident and cheerful. She loves "Kero-chan" and his friends, but is usually away from home working.

Akina Hinata

Voiced by: Hisako Kyoda (Japanese), Linda Leonard (English) and Nuria Marín Picó (Spanish)

Aki's mother, and Fuyuki and Natsumi's grandma. A wise old woman who lives out in the country. Considered and revered by Keroro Platoon as the top-ranking "officer" in the Hinata clan, above Aki.

    Close Pekoponian Friends 

Momoka Nishizawa

Voiced by: Haruna Ikezawa (Japanese), Monica Rial (English) and Nuria Marín Picó (Spanish)

Heir to a multi-billion-dollar international corporation, Momoka seems sweet and innocent at first, but has a hidden dark side related to her obsessive crush on Fuyuki. Spends tons of money on various Zany Schemes that she hopes will help her get closer to him, with little success.

Paul Moriyama

Voiced by: Keiji Fujiwara (Japanese), Kent Williams (English) and Miguel Ortiz (Spanish)

Momoka's personal servant and Battle Butler. Always on hand to tend to her every need and slightest whim, no matter what it calls for. Also serves as a surrogate parent of sorts, as her parents are almost always off doing their own thing.

Mutsumi Hojo/Saburo

Voiced by: Akira Ishida (Japanese), Joel McDonald (English) and Jaime de Diego (Spanish)

An extremely laid-back, smooth poet and artist who has an Odd Friendship with Kururu and serves as Natsumi's Love Interest. Runs his own radio show, and carries a special pen that lets him bring his drawings to life.

Koyuki Azumaya

Voiced by: Ryo Hirohashi (Japanese), Luci Christian (English) and Sonia Torrecilla (Spanish)

A cute, cheerful Ninja girl who found Zeroro and brought him back to her Hidden Ninja Village, befriending him and eventually accompanying him to the city, where she transferred into Natsumi's school and helped him locate the others.

The Narrator

Voiced by: Keiji Fujiwara (Japanese), R Bruce Elliott (English) and José María Regalado (Spanish)

Exactly What It Says on the Tin.

Tomosu Hinohara

Voiced by: Emiri Kato

Myou Kaneami

Voiced by: Ai Kayano

    Pekoponian-like Aliens 

Angol Mois

Earthling disguise
True appearance

Voiced by: Mamiko Noto (Japanese), Carrie Savage (English) and Ana Begoña Eguileor (Spanish)

The surprisingly cute Lord of Terror who was sent to destroy Earth as according to the prophecy of Nostradamus. Only she kind of missed her cue, and Keroro manages to convince her not to go through with it by virtue of being her beloved "Uncle". Sort of an honorary Sixth Ranger of the Keroro Platoon, though for obvious reasons she can't show off her moves all that often.

Space Detective Kogoro

Voiced by: Nobuyuki Hiyama (Japanese), John Swasey (English) and Anselmo Herrero (Spanish)

An old childhood friend of Keroro's, Kogoro is a Space Detective who always seems to be down on his luck. Despite this, he always seems cheerful, laughing and grinning no matter what he might be thinking.


Voiced by: Tomoko Kaneda (Japanese), Leah Clark (English) and Ana Guadalupe Hernández (Spanish)

Kogoro's younger sister, and the only one who can tell how he really feels at any given moment. As a result, she frequently has to act as a "translator" of sorts. Does her best to support her brother by taking various part-time jobs.

Alisa Southerncross

Voiced by: Akiko Yajima (Japanese) and Estívaliz Lizárraga (Spanish)

An Emotionless Girl adopted by the Shapeshifting alien Nebula, who rides around as her cat-eared headband and fights for her. He takes out her opponents and eats aliens, all while searching for a way to help her become human. Alisa, for her part, seems entirely uninterested in this... but shows some interest in Fuyuki.

    The Garuru Platoon 

First Lieutenant Garuru

Voiced by: Akio Ohtsuka (Japanese)

Giroro's Aloof Big Brother, a famous sniper and hero of Keron Force. Was given his own platoon, and was assigned to confront and replace the Keroro Platoon. Cue the Wham Episodes.

Private First Class Taruru

Voiced by: Akeno Watanabe (Japanese), Chris Cason (English) and Estívaliz Lizárraga (Spanish)

A cute, if insanely energetic, tadpole who absolutely adores his "Master Tamama"... And, rather obviously, was tapped to be part of the Garuru Platoon, where he cheerfully played Evil Counterpart to Tamama. Often puckers his lips up in a sort of "kissy face" expression.

Lance Corporal Zoruru

Voiced by: Kazuki Yao (Japanese)

A half-cybernectic assassin who appears to have joined the Garuru Platoon just to get a crack at Zeroro. Would probably love to be a Knight of Cerebus, if given the chance. Unfortunately, he tends to be even more forgotten than Dororo...

  • Artificial Limbs: A full half of his body, bisceted down the middle, has been replaced with robotics.
  • Berserk Button: Being ignored.
  • Black Eyes of Crazy: Zoruru had this during his childhood, and it only got more menacing when he became an assassin.
  • Cyber Cyclops
  • Determinator
  • Evil Counterpart: Towards Dororo, whom he insists on calling 'Zeroro'.
  • Failed a Spot Check: Like Dororo, ends up on the other end of this several times. One chapter plays with this, as he sits in on a meeting with the Keroro Platoon, taking Dororo's usual spot so that the reader's eye may glide right over him without seeing anything amiss... despite having just seen Dororo leaving with Koyuki. That's before the others take it Up to Eleven.
  • Freudian Excuse: Volume 17 of the manga revealed he apparently attended the same school as Keroro and Zeroro, and was completely ignored when those two first met... despite standing directly behind Zeroro at the time.
  • Hollywood Cyborg
  • Knight of Cerebus: During the Garuru Platoon's invasion, he defeats and seemingly kills several of the Keroro Platoon's allies in rather nightmarish fashion, only to have this Subverted by an Anticlimax. Attempted again in Volume 17.
  • Not So Different
  • Red Eyes, Take Warning: One eye, red pupil, black sclera. Judging from the Flashback in Volume 17, these are his natural eyes.
  • Unknown Rival: He's perfectly capable of being an excellent rival to Dororo... if he wasn't so forgettable that literally everyone stops noticing him with in seconds. He has to go out of his way to get people's notice.
  • Verbal Tic: Dramatic stammering, as in "Z... Zeroro..."

Recruit Tororo

Voiced by: Kappei Yamaguchi (Japanese)

An incredibly irritating tadpole who hacked into Keron Forces' computer once, got caught and was promptly recruited. Considers himself Kururu's rival, and longs for the chance to put him through the ultimate Humiliation Conga.


A Sixth Ranger of sorts for the Garuru Platoon's debut, with very different origins in the manga and anime. The manga version is a Creepy Child clone intended to "replace" Keroro, while the anime is a deaged, Brainwashed and Crazy Keroro.

Chief Medic Pururu

Voiced by: Satsuki Yukino (Japanese)

A childhood friend of Keroro, Giroro and Zeroro. Originally a civilian medic, she got bored and joined the military, ending up assigned to the Garuru Platoon.

    The Shurara Corps 


Voiced by: Norio Wakamoto (Japanese)

The leader of a group of anime-only villains who are out to steal the Keron Star from Keroro. Notably, all of the members were based on fan-submitted characters, meaning they all ascended to anime canon. The whole arc turned into a giant Monster of the Week-fest.

Master Painter Putata

Voiced by: Kentarou Tone (Japanese)

A spotted yellow Keronian who can bring his paintings to life. Highly excitable.

Super Marionette Mekeke

Voiced by: Cho

Putata's partner in crime and a master puppeteer who conceals himself via invisibility while fighting with his puppet.


Voiced by: Kunihiko Yasui (Japanese)

A mutant Keronian made of pure blue slime. Can transform others into mutants like him, but is weak to anything that can make him solidify.


Voiced by: Takeshi Kusao (Japanese)

A ghostly Keronian with a heavily scarred face, a scythe blade replacing his left hand, and a demonic symbol.


Voiced by: Toshio Furukawa (Japanese)

The assassin of the Shurara Corps, an older tadpole who can manipulate shadows.

Seamstress Nuii

Voiced by: Kurumi Mamiya (Japanese)

Once an abandoned Keronian doll, Nuii was brought to life by Shurara and made into one of his agents. She had the ability to turn everyone into plush dolls like herself, and under Gyororo's supervision, inflitrated the Hinata household in the guise of Natsumi's old teddy bear.


Voiced by: Hiromi Hirata (Japanese)

Nuii's superior, a Keronian covered in Extra Eyes who can blend into his surroundings, making him a perfect spy.


Voiced by: Keiichi Sonobe (Japanese)

A robotic Keronian with scanner eyes, magnetic hands, built-in jets and the ability to fuse others with nearby mechanical objects.


Voiced by: Eiji Maruyama (Japanese)

A snowman Keronian who can summon massive gusts of arctic winds and freeze everything around him. However, he's weak against any sort of heat.

    Other Keronians 


Voiced by: Kenichi Ogata (Japanese) and Greg Dulcie (English)

Keroro's famous and terrifying father. The mere mention of his name sets off all kinds of Parental Issues for his terrified son. However, in person, he seems to be rather laidback...


Voiced by: Sachiko Chijimitsu (Japanese)

Keroro's mother who first appeared in the KeroZero short shown before the 4th Movie. She's very loving toward her son like a good mother, but she also seems to have a tricky side to her.

  • Amazingly Embarrassing Parent: She just loves to go around and talk about how wonderful her son is while offering sweets. She does this to everyone, much to Keroro's chagrin.
  • Body Snatcher: Although Natsumi was the one who had the idea of switching bodies with her, with the consent of both, afterwards she just disappeared with Natsumi's body, going to sight see Pekopon and even on a date with Giroro (Even though he knew it was Keroro's mother) while Natsumi in her body got dragged to another city by Keroro's father, who didn't believe any switch had happened.
  • Doting Parent
  • Generation Xerox: Her son definitely got her looks.
  • Mrs. Robinson: She actually went into this on Giroro.
  • Shout-Out: Her design is very reminiscent of the mother in Atashinchi, who was voiced by Kumiko Watanabe, Keroro's voice actor.


Giroro and Garuru's father. Appears to have a reputation just as terrifying as Keroro's father, though he's not mentioned as often. Makes a habit of turning even the simplest tasks into 'tests' for his sons.


Dororo's mother. Looks exactly like her son (in a dress), and apparently passed down a lot of her personality traits, too. Whenever she sees Keroro, Giroro or Pururu, she immediately thanks them for being friends with Zeroro. Repeatedly. Over and over and over...


Voiced by: Junko Noda (Japanese) and Alison Viktorin (English)

An extremely cute Keronian tadpole, Karara is an extremely naive daydreamer who dreams of finding her Knight in Shining Armor and falls in love at the drop of a hat with anyone who helps her out. Avoids Stalker with a Crush mainly because she runs off and does her "Bridal Training" offscreen, then shows up childishly expecting to have her affections returned...only to transfer her crush to someone else and start the whole process over again.


Voiced by: Natsuko Kuwatani (Japanese)

Karara's fraternal twin sister. Doesn't appear as much or get as much character focus as her sibling.


Voiced by: Junichi Sugawara (Japanese)

An anime-exclusive character based on a fan submition, Joriri is an unshaven bum who appears in various flashbacks, giving the young Keroro, Giroro, Zeroro and Pururu questionable advice and generally being a poor role model. May have been introduced to add an "adult!Keroro" style character to the past, even though the younger Keroro already filled that role. Recently showed up in the present, much to the dismay of fandom.

  • Ascended Fanon: Joriri was originally one of the fan designs submitted to the Keroro Land mangazine, before being incorporated into the tv show.
  • Ice-Cream Koan: His big gimmick involves imparting an extremely odd form of sage wisdom that doesn't make a lot of sense.
  • Perma Stubble: Not an action hero, though.
  • Sixth Ranger: He joins the Keroro platoon in the 6th season... for one episode. Although that event is still referenced later.

Assassin Captain Jirara

Voiced by: Kouji Yada (Japanese)

Leader of the X1 assassin troop on Keron, and Zeroro's trainer in the art of killing. Cold and merciless and wanted in several galaxies, it only makes sense that he popped up on Pekopon...

  • Artificial Limbs: It almost seems like this is a requirement for spooky assassin-types.
  • Drill Sergeant Nasty/Sadist Teacher: Jirara trains his underlings by making them constantly fight each other nearly to the death. If you die, you were a bad student anyways.
    • However, a Flashback in Volume 17 of the manga reveals that he deliberately chose a Lighter and Softer alternative to making Zeroro a full-fledged assassin, despite acknowledging that Zeroro had excelled in his training. When his pupil begged for an explanation, Jirara tells him flat-out that the assassin's path is "darker than you can even imagine".
  • Giant Spider: He takes on this form in Dororo's nightmare.
  • Red Eyes, Take Warning

Warrant-Officer Bariri

Another character solely from the anime. Despite his rank and the respect he apparently has, he's very... Crazy. Most of this is put in the direction of his unhealthy infatuation with Pururu. Really, really unhealthy.

    Other Aliens 


Voiced by: Juri Ihata (Japanese), Caitlin Glass (English) and Sonia Torrecilla (Spanish)

A pink Keronian-like alien, known as an Axolotl. She's a highly popular and very spoiled Idol Singer who likes to pull Ratings Stunts.


Voiced by: Nobuo Tobita (Japanese) and Chris Patton (English)

An alien race of humanoid snakemen, the Vipers are natural enemies of Keronians and are dangerous, deadly predators. Most of the Vipers that show up in the anime have a personal vendetta against the Keroro Platoon, thanks to what happened to the first Viper that targeted them. In the manga, on the other hand...

    Movie-Exclusive Characters 


Voiced by: Mikel Gandía (Spanish)

A sort of ancient Keronian super weapon that feeds off of negative emotions to gain strength and destroy planets. While not necessarily movie exclusive, they're a very big element of the first and third movies, and become a victim of the Worf Effect in the second. In the first movie, Keroro and Fuyuki accidentally unleash one on Tokyo.


Voiced by: Estívaliz Lizárraga (Spanish)

An ancient Keronian weapons specialist that sealed away the first Kiruru, but got stuck in the proverbial can with him as well. She works off of positive emotions, and is able to turn into a key, the only thing that can reseal the Kiruru and save the world.


Voiced by: Estívaliz Lizárraga (Spanish)

A Maronian living at the bottom of the ocean who was feeling lonely one day and as a result, abducted Natsumi to be his princess. In the end, all he wanted was a mother figure rather than a princess.


Voiced by: Rosa Romay (Spanish)

The only other friend Meru has, despite the fact he treats her like his servant and is generally unpleasant to her. Regardless, she remains chipper and incredibly loyal to him.

Dark Keroro

Voiced by: Nuria Martín Picó (Spanish)

The primary antagonist of the third movie. Cloned from a sample of Keroro's own DNA, taken off the Kero Ball when it was lost in an ancient Keronian facility hidden in the ancient city of Macchu Picchu in Peru.


Voiced by: Estívaliz Lizárraga (Spanish)

  • Arrogant Kung-Fu Guy
  • Evil Counterpart to Tamama
  • Homage: to Sun Wukong of the Journey To The West tale that Dragon Ball was based on. Note his 'symbol', which is really a band around him that resembles the flying cloud, while resembling Wukong's Restraining Bolt. He even uses the original 'Great Saint That Surpasses Heaven' title when he first appears.
    • He's also a pretty direct reference to Goku from Dragon Ball. He uses a blue blast of energy at one point charged up similarly to the Kamehameha and, in the final battle, attempts to use the Genki Dama while fighting against Tamama and Momoka, even calling up for other people's power. One of the scenes featuring him in the credits sequence is a homage to Dragonball's original ending and another one shows him in a place very similar to the Tenkaichi Budokai tournament from Dragonball, fighting against someone with the body obscured, but wearing pants and shoes identical to Yamcha's in the 22nd and 23rd Budokais.
  • Weapon of Choice: A Simple Staff WITH LASERS.


Voiced by: Txemi del Olmo (Spanish)


Voiced by: Rosa Romay (Spanish)

Appearing at the same time as Dark Keroro, she's the only one capable of operating their Ominous Floating Castle, but there's something about her that even he doesn't know...


One of Momoka's old friends, and shares a lot in common with her - except that her rich parents passed away early on. All she wanted was a real family, and from the depths of Mont-Saint-Michel, someone answered...


When Shion attempts to breed the Earth Dragon egg hidden under Mont-Saint-Michel, the plan reaches frution and the massive Earth Dragon is hatched - but the destruction it causes to the world forces Shion to intervene, and eventually the Earth Dragon relinquishes its power, turning into a harmless little creature that resembles a salamander-based Keronian.

  • Superpowered Evil Side: The Earth Dragon form, though it's officially sealed away by the end.
  • Meaningful Name: Terara comes from 'terra', meaning Earth. Can also be read as referring to terror...
  • Nice Hat: Shion's beret is passed to Terara at the end.


Shion's legal guardian, very similar to Paul in more ways than one can imagine.

Alternative Title(s):

Keroro Gunsou