|Alias||"Nibs/Nibikko" (by Ginshu)|
|Birthday||January 24 (Aquarius)|
|Status||Deceased (Episode 9)|
|Affiliation|| Mud Whale|
|Friends|| Ouni |
Nibi has blond hair that reaches his chin and blue eyes. He wears a blue and brown open vest and grey pants. He doesn't wear any shoes.
Nibi has a boisterous personality. Although he pretended to be confident, he was secretly terrified that Ouni would leave him behind. He was also content with staying on the island, so long as he could stay by Ouni.
He was the original leader of the Body Moles, before they acquired that name. Before the start of the series, he attempted to get Ouni to join his group of friends, but the two got into a fight and were sent to the bowels of the ship to get along better. There, Nibi learns of Ouni's wishes to see the outside world, and promises to take him there.
Nibi, along with the rest of the Moles, is freed from the belly of the ship after the rain. He excitedly questions Suou alongside the other Moles after they learn that a girl was found from outside of the Mud Whale. Later, he can be seen with part of the Moles during the first attack on the Mud Whale, and witnesses Aijiro and Buki's deaths.
After the attack, he hangs with Ouni, and remembers their past together. He tells Ouni that he wishes that he could be as strong as he was, and not cry. When the Skylos infiltration force is chosen, Nibi tags along, even though he was not chosen.
He is injured during one of the attacks, and ends up staying behind with the group guarding the door. When he hears Ouni getting shot, he runs out to help him. Together, he and Ouni take down Pagoni. However, when he turns his back on the enemy to look towards Ouni, he is stabbed through with spears, and dies.
Nibi later speaks to Ouni posthumously, and tells him that he was happy simply being by his side.
Ouni - His best friend. They've known each other since they were children. Nibi dreams of going to the outside world with him. He secretly worries that Ouni will end up leaving him behind.
Nibi is named after a Japanese color meaning "dark gray". 
- ↑ Volume 2, page 192
|Mud Whale||Chakuro | Lykos | Sami | Suou | Taisha | Kuchiba | Shinono | Masoh | Ouni | Kicha | Ginshu | Shuan | Siena | Hakuji | Lasha | Kogare | Kikujin | Miru | Shikoku | Shikon | Nibi | Neri | Aima | Byakuroku | Dyo | Ekato | Miden|
|The Empire||Orca | Liontari | Arachni | Itia | Atsali|
|Kingdom of Siderasia||Rochalizo | Dictis | Adihilas | Palamesosu | Daktila|
|Other||Olivinis | Kokalo | 王子 | 宮廷道化師 | 国王 | 女道化師|