Corporal Sununu is a female teal keronian, and has yet to lose her tail. Her friends include Tamama, her childhood friend and "boss" Jururu/Jaylen, and Giroro, who she has a tremendous crush on.
When Sununu was very young (a few Pekoponian years before the Keron War), she was contacted by a secret experimenting "company" on the underbelly of Keron. The team of researchers had assembled a team of young Keronians for testing their project called the: "Morph Bracelet". Sununu never knew quite why she had to take part in this, but she did. At the time, she had no idea what it was, but learned at some point during her teenage years in the war that it could morph you into any alien, so long as you had the required bead. This gave her a leg up when fighting in different climates, as she created her own forms of hundreds of species. After the war, apon the arrival of the news that the remainder of her friends (aside from Jururu, now ranked as a Sergeant Major) were dead, the two traveled the galaxy, but stopped short at Pekopon. Learning how accustomed to aliens the Hinatas and their friends were, Sununu and Jururu created an aliance with the Keroro Platoon and all affiliates. When on Pekopon, Giroro saved Sununu from being hit by a car while invisible. Sununu admired his bravery and quickly fell in love with him.
- Giroro: Sununu has a huge crush on our red corporal, and shares a title with him. The funny thing is, Giroro complains about Natsumi being oblivious to his feelings, when Sununu often directly tells him she loves him, to which he replies, "Hmm?"
- Jururu: Sununu and Jururu grew up together, and are practically sisters.
- Tamama: Tamama and Sununu relate very much. Both become very defensive when loved ones are at stake, or when anyone comes close to their love. Often the two will talk about Sargent Oblivious and Corporal Unobservitive.
- Natsumi: Sununu hates Natsumi with a passion, and despised her even before falling in love with Giroro. At first, she thought Natsumi was "Too pretty, too smart, too tough, too athletic... TOO PERFECT!" and when she learned Giroro had his eyes set on her, all that did was give her a chance to hate Natsumi even more. However, (just like Mois to Tamama) Natsumi appears to be 100% unaware of this.
- Dororo: Dororo was very pleasant to Sununu, and he would listen to her rants about Natsumi and Giroro, and sometimes he would mention to Giroro how lucky he was to have a secret admirer.
- Aeroro: Aeroro is Jaylens adopted brother, and since Sununu is practically Jaylen's sister, Sununu became slightly jealous of Aeroro's attention. After a while, the attention faded, but Sununu repays him by yelling at him, forcing him to do stuff, and other things of the sort.
- Kululu/Kururu: Ever since she met him, Sununu was creeped out by Kululu and his sadistic demeanor. He often uses Giror and Natsumi against her. She is often used for experiments and tests, but later she found out his secret, and used thisagainst him, but she feared him to much to do any major damage.
- Sununu loves Popcorn and only lets Giroro take some away from her.
- Despite Neko/Miss Furbottom also having an interest in Giroro, Sununu gets along very well with his cat, and even feeds her occasionally.
- Sununu calls Jaylen "Jururu" when she's mad.
- Sununu goes to Natsumi's High School in her Pekoponian form.
- Sununu has wings and fangs, results from morphing so often.
- Only Kururu knows her deep dark secret: She has a Giroro plushie she stole from the leftover merchandise from Ep. 19. (Jaylen learned this later on as well).
- Once, Kululu separated Sununu from her group to measure her strength. At first, she seemed unfazed by the fact, so Kululu merely told her Giroro was on the other side of the wall talking to Natsumi. She promptly destroyed the wall by punching a hole clear through it about 5 feet wide and 3 feet tall.
- At Jaylen and Dororo's wedding, she was the maid of honor.
- Sununu once found a photo of Natsumi. She literally TAPED the pic to a dartboard, and threw darts at it until she landed square inbetween the eyes.
- Sununu watched 300 with Giroro on her birthday (but she wouldn't tell anyone how old she was!).
Sununu never talks about her parents. She often says that Jaylen is her only family. Arrival at the Hinata's made her sad at her own lack of family, seeing how Natsumi would die for her brother and mother, and how they would do the same for one another. One day Tamama noticed, and he told her not to be sad, because "We can be your family!" and he handed Sununu her Giroro plush. To this day, she calls the platoon and Hinatas her family, and Jaylen still remains her sister.
- Age: Unknown- most likely younger than Jaylen
- Gender: Female
- Blood Type: AB
- Date of Birth: November 17
- Species: Keronian
- Marrital Status: In love with an oblivious and inobservitive... frog
- Extras: Black scaly wings; fangs; poor eyesight via Pekoponian form