Kururu (クルル), or Kululu, is a main character in the anime and manga series Keroro Gunso. He is a Sergeant Major (曹長 souchou) [RANKS] and the Strategy and Communications Staff Officer of the Keroro Platoon.
Kururu's name has been romanized as 'Kululu' in the English manga as of the eleventh volume. Furthermore, all of the books previous to this have been republished with the name replacement. In the manga Kururu stated that Kululu is his stage name.
Kururu is a yellow adult Keronian with a small yellow spiral symbol on his orange cap and a red spiral on his belly. His headphones are a multipurpose gadget and have been seen performing a multitude of tasks. He wears white glasses with spirals on them. His eyes have never been seen, but it's likely that his eyes are green, as when he's in his dragon form and when he's in various Pekoponian costumes, his eyes are an olive-green. But once his eyes revealed to be dark aa seen in episode 240th. When his glasses are taken off his eyes resembles a kissyface emoticon, or a 3. 
When Kururu was a young child, he was originally blue, but was then dyed yellow after falling into a huge plate of curry created by the Kero Ball. When he was blue, he seemed normal though admittedly a little off, but it seems like something changed when he drowned in the curry. He seemed to develop a much darker personality and the constant shadow over his face.
His afro was first seen dark orange but later, and more often, is seen as purple.
Although he is ranked higher than Keroro, Kururu is not the leader of the Keroro Platoon due to his unpleasant and unnerving demeanor, which has given him the nickname of 'Yellow Devil'. He is mostly known as a sadist and egoist. His blood type is AB, which fits his personality.
According to annotations in Mine's concept art about his younger self, during childhood, Kururu was seen as a well behaved and loving child. However, even at this point, he had an ominous grin that showed his eventual nature. It was after an incident where he absorbed hot curry spice into his body his personality became outwardly twisted and his genius intellect reached an even higher level, attracting attention of the Keron Army.
Kururu's personality is complex. Going by the differences in the way he conducts himself when speaking to others and the way he speaks in his own head or when he's alone, it seems like his way of being so creepy and enigmatic may just be a facade to put people off or conceal his thoughts.
Kururu shows a lack of empathy, along with social problems, difficulty making friends and interacting with people, and he is inclined to avoid others. He also seems to have problems with eye contact, posture, and other social gestures, along with a failure to react "appropriately" to various situations. He has restricted interests and seems to get bored easily. He is often seen with a video camera recording events, and is shown to have a massive room of shelves upon shelves upon shelves full of DVDs with seemingly unnecessary information on them, like random footage of a brook. Kululu is also shown to crave or at times fail to notice pain and he mysteriously enjoys terrible sounds, such as nails on a chalkboard.
Despite these idiosyncrasies, he is a very intelligent man and he is full of wisdom. His place on the platoon is stable, and it has been shown more than once that they can't do very well without him. Sometimes he can be a prankster and cruel. As shown in episode 28b of the anime, he has tortured everyone with his pranks. In episode 49a, he messed up Natsumi's laundry and ripped some pages out of Fuyuki's book.
Despite appearing to care for the select people he likes, Kururu is extremely mischievous and enigmatic, almost to the point where some people might call him a mad scientist. Most of the characters see him as a depressing jerk and in the series, action figures of him tend to sell very poorly on Keron (much to Kululu's displeasure).
It is apparent throughout the series that the way he responds to things and how he acts is carefully controlled. He seems to want to keep up his appearance of being heartless and uncaring. When the Soul Diver is used on Kululu, it is shown that he controls even his thoughts this way, as things are organized and even labeled.
He does seem to be self-conscious about his appearance, as he tends to freak out when he's referred to as ugly and unlikable (first encounter with Tororo, turning on the narrator, the new years episodes).
Realistically, however, he is actually a fairly good person who cares for his friends. He just likes practical jokes and often takes them too far.
Kururu is the brains of the Keroro Platoon, officially in charge of intelligence and planning.
Kururu also seems to be a skilled DJ. He is seen in a few episodes using turntables (one time in front of a large crowd).
Kururu loves curry, and seems to be very obsessive about it.
Kururu is revealed to be deeply afraid of Angol Mois' purity, likely due to it making him feel guilty about himself, as shown in episodes 28b and 123. Another weakness is curry and whenever it is around Kururu almost compulsively eats it. He is even seen bathing in it, and can withstand even the spiciest curries. He is often seen holding a plate of curry or loudly eating it.
Along with the other members of the Keroro Platoon, Kururu is afraid of Ketsubakuchiku.
Costumes and Transformations
- Kururuko (クルル子)
In some episodes, Kururu dresses as a magical girl complete with short, orange hair, a uniform, a wand and wings.
Kururu became Keroro's guide in Hinamatsuri. He also became a contestant for 623's radio contest, in which he won, by doing confusing math while telling cold jokes. In another episode, he became a very popular idol under the name Kururuko Tsukishima, and later suddenly quits and disappears right before a big stage performance for the despair of Keroro, who is acting as his manager.
After turning himself into a baby using his age-altering gun which broke soon after, Kururu was seemingly stuck in this infantile state. This caused much trouble for everyone. The Hinatas take care of him while the platoon look for blueprints. However, when the very affectionate Angol Mois puts him up against the terrifying idea of being raised by someone as pure and innocent as her, he quickly fixes the gun, apparently retaining his genius even as a baby, and turns back to normal.
- Old Lady
- Pekopon suit
Keroro gives the Keroro Platoon an order to find the wanted criminal #303, Kururu dresses up as cop wearing a brown hat and matching trench coat.
- Frankenstein's Monster
Kururu dons this attire in order to attend a Halloween party in episode 133 of the anime.
- Galaxy Group Grunt
When Mutsumi sent Fubuki Sakuragasaki to face Keroro in an Arcade Game challenge with Earth's fate on the line, he also changed Kururu, who oversaw the match, into this form, which mimics the appearance of low ranking members of the antagonists of Arcade Gamer Fubuki to hide Kururu's true nature.
- Dragon Kururu
During the fourth movie, Shion captured Kururu and turned him into a dragon. In this form, he is a yellow dragon with metallic blue wings. He loses the glasses in this form, revealing yellow green eyes. On his chest is a warped spiral symbol, and his headset has cords protruding from them, allowing him to utilize electrokinesis.
In episode 356-A "Keroro platoon, real Dragon Warriors", his eyes once again were shown to be yellow green, although the backside of his wings were yellow like his body.
Ryusei is introduced as a singing dancing idol invader, part of Operation
Maru-Otsu (〇乙) unit. However, he's actually an android remote controlled by Kururu. Kururu researched tastes of Pekoponian girls and created 5 androids that fit their preferences. Kururu controls Ryusei using the Invasion Substitute System through a special control room and full body suit hidden inside the Keroro Platoon Headquarters.
Also known as Kururu Girl Type, and she also calls herself Kururuko. The female human form taken by Kururu due to the effects of a mysterious substance known as Sandstar in a collaboration with the original Kemono Friends mobile game. In this form, Kururu has bright yellow eyes. Aside from physical appearance, voice and personality also change. Her voice actress is Emi Uwagawa. She's the closest to her standard self compared to the other platoon members, speaking in the same way and mostly acting the same. However, she's more peppy than usual and after joining the player's party is actually rather friendly with the player character.
In the Handsome Keroro Gunso Invasion Operation, a collaboration with the Smiral merchandising label, the Keroro platoon become handsome men due to an invention created by Kururu in order to become popular with girls to obtain more invasion funds.
He created a scale giant robot of Aki (AK966) and said a lot of things referencing that he admires her. The platoon tried to use her to make him "love struck" to distract him from his one day as leader in episode 311a. Despite his affections for Aki, he is not above calling her an "idiot" or pointing out her faults when she does something reckless or foolish, as shown when she lets her giant robot get out of control.
Saburo is Kururu's Pekoponian partner on Earth. He is the only one in the whole show who likes Kururu as a friend, most likely because Saburo is non-judgmental and does not pry into Kururu's business. When Kururu first came to Earth, he gave Saburo one of two Reality Pens. Even with their closeness, Kururu prefers to live in his lab rather than with Saburo, but despite this, he was at least shown on one occasion to accompany Saburo on his radio show where he would watch Saburo speak.
Saburo also has a small relationship of understanding Kururu.
Kururu has a healthy fear of Natsumi. He has been abused by her countless times in the past, and even states "Nacchi is scary!" However, he still continues to take pictures and video of her in the bath. He uses these to help out with the platoon's budget. Despite his occasional fear of Natsumi, he is not above helping Keroro in getting revenge on her and is usually the one to invent a device that will humiliate or defeat her. When Dasonu Maso tried to invade Pekopon, MorePeachSummerSnow (consisting of Natsumi, Koyuki Azumaya, Mois and Momoka Nishizawa saved the city by dancing and singing. Unfortunately Kururu taped the whole thing which angered Natsumi.
Rinono and Shupepe are Kururu's childhood friends and older siblings. Before he was dyed yellow, he would walk from school with them.
Being Kururu's leader, Keroro recurrently uses Kururu for the majority of 'important' missions, seeing how he's the specialist in this field. Kururu has been prone to show he works best under orders and influences as he is lazy and unmotivated. It's common to see Keroro devising a plan with Kururu throughout the series. Together, they make a good team. However, when inventing something for Keroro, it is occasionally designed to backfire, go out of control or torment his fellow Platoon members simply for Kururu's own amusement. In episode 170-a he told Keroro of the seventh wonder of Kissho Academy, but deliberately left out that something horrible would happen to anyone that knew of it. Despite Kururu's general mischief, he is aware of Keroro's rank and usually listens to him when he gives a command.
Giroro does not like Kururu due to opposing ideas (brain vs. brawn). Despite this, Kururu loves to use Giroro as a guinea pig for his experiments or simply torment him whenever possible. He takes great delight in torturing Giroro whenever ordered to by Keroro during plans that involve taking down Natsumi, and he seems to enjoy seeing Giroro fail pathetically in his relationship with Natsumi. Kururu and Giroro's relationship is sorta complex.In episode 147, Kururu gives Giroro a heart-shaped box with curry roux inside. It's unknown if Kururu was trying to troll Giroro or he actually likes him. Another episode 157, Giroro got knocked out by a rock and Kururu decided to do "mouth to mouth" while blushing
Dororo and Kururu appear only as acquaintances. Kururu is usually instructed by Keroro to make a variety of different technology to help with Dororo's frequent, "Trauma Switches" such as in Ep. 238B and 351A. Of his own will, Kururu enjoys taunting him and calling him "stubborn" or "annoying" each time he hits his depressing state, seeing how it shows both of their inner weaknesses. (ep. 349A) Like the rest of the Platoon, he regularly forgets about Dororo, but unlike the rest of the team, he barely ever acknowledges Dororo's existence.
Kururu views Tamama as an annoyance and "little brat". Tamama envies Kururu's strength in hacking, but Kururu shows very little interest in Tamama's power. Like the rest of his victims, Kururu enjoys playing pranks on Tamama or using him as a guinea pig and once willingly went out of his way to make a mind controlling notebook that would eventually drive Tamama over the edge.
Kururu and Angol Mois do not usually interact but when they do, it is quite clear that Kururu cannot stand her as she comes off as a shining and innocent soul which contrasts with his own dark and selfish personality, making him feel exposed. He also despises the fact that she is immune to his psychological mind tricks.
Tororo is Kururu's self-proclaimed nemesis on the Garuru Platoon. Tororo always tries to one up Kururu, but Kururu only sees Tororo as a nuisance and Tororo is easily defeated by him.
Kururu's name comes from the Japanese word for the
kurukuru (クルクル) meaning "round and round," , referring to the spirals seen on his glasses and explaining why his resonance goes "round and round".
His name may also come from the incurable brain disease named Kuru. The term "kuru" derives from the Fore word "kuria/guria", 'to shake' a reference to the body tremors that are a classic symptom of the disease; it is also known among the Fore people of Papua New Guinea as the "laughing sickness" due to the pathologic bursts of laughter people would display when afflicted with the disease. This may also refer to Kururu's insane 'Kukuku~' laugh.
Although the younger Kururu is shown with a pacifier most of the time, Mine's concept art for him includes a comment saying that he's only a little younger than Chiroro and Karara.
- Kururu has a habit of eating everything very quickly and loudly.
- He was once ranked Major in the army as an intelligence officer, but was demoted for causing trouble for the 'higher-ups'.
- Kururu has cried very few times in the series:
- Kururu calls himself "Ore" or "Ore sama" in the anime (like Giroro), denoting that he places himself higher than the rest of the platoon. 'Ore' is an arrogant and masculine way to address oneself, and adding 'Sama' to the end of it makes it even more presumptuous.
- He can play the recorder.
- He often says "Nyu" at the end of his sentences(Japanese dub)
- Kururu has this habit of picking his nose
- There have been a few occasions where his trademark "ku-ku-ku' laugh has been replaced with 'Shishishi'.
- Despite the fact that most of his inventions are shown are to be defects, Kururu himself states that he creates his inventions to think above their original program. 
- Kururu listens to songs by The Idol Master and he even has a CD.
- In episode 159b, Shurara called Kururu as "the man who makes the impossible possible". This is an actor allusion to Mu La Flaga from Mobile Suit Gundam SEED, whom shared the same voice actor with Kururu, Takehito Koyasu.
- In the dubbed version of the "Lost in Transportation" episode, Kururu takes a "What kind of muppet are you?" quiz and discovers he is Miss Piggy.
- Kururuko's stage name, Kururuko Tsukishima, is a reference to Kirari Tsukishima from Kirarin Revolution, an anime about a magical girl who wishes to become an idol much like Kururuko does in the episode.
- Kururu's voice actor, Takehito Koyasu, also voices Dio Brando from the 2012 anime adaptation of JoJo's Bizarre Adventure, based on the 1987 manga of the same name.
- A common running gag in the series is where Kururu sometimes shouts "Pochito! (ポチト！), which literally means "I press this" or "Click", whenever he presses a button.
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