Kokuryuu Kaguya is the main protagonist of the Battle Rabbits manga series. He holds the golden jewel in his chest signifying himself as the ruler of all Battle Rabbits. Together with Mao, he fights against Org that invade the Earth as a member of Genou.
Kaguya is a young boy with medium length dark brown hair and bangs that fall neatly onto his face. His eyes are reddish-brown, and he wears a white button shirt below his black gakuran. He has a nicely built body.
When he transforms into a battle rabbit, bunny ears appears on his head along with a bunny tail on his behind. He is able to pull out a big sword from his golden jewel out of his chest.
His bunny ears later change into wings.
Kaguya is a cheerful, kind, and selfless person. Despite catching Kousuke shoplifting, he didn't tell on him but gave him a lecture instead. As a baby, he is shown to be smiling a lot around those close to him. He deeply cares for his father and plans to avenge his father's death. To Kaguya, losing someone such as Izumi is more painful than him losing his arm.
Kazuharu found Kaguya under a bridge, picked him him up, and raised him as his father. He considered his father as his treasure. When Kazuharu died, Kaguya was sent to an orphanage where he was soon adopted by Kazuharu's parents. When Kaguya's grandfather died, his grandmother had been strict and abusing towards Kaguya. She went as far as slamming his head on the wall, hitting and starving him. After much abuse, Kaguya had ran away from home to commit suicide by drowning in a river and got infected by an org, but was stopped and saved by Hijiri in his battle rabbit form. Kaguya had thought Hijiri was Inari-sama to which the latter played along to. Hijiri brought Kaguya back to his house where he killed the org possessing Kaguya's grandmother. Suzune had came to get Kaguya from her mother to raise him herself after hearing from her uncle about the condition Kaguya is in. From then on, they've been living together in an apartment.
As a young boy, when Kaguya's classmate insulted Kazuharu, Kaguya would get upset and give them a beating.