Jukokubo is the main antagonist of the terrible Oav Dark Cat. He was the master of Hyoi and Ryoi, until he left them and became the leader of all the demons and released his evil on earth. He was voiced by Daisuke Gouri.
In the past he was a master of the dark cats arts and trained two young boys called Hyoi and Ryoi, with time he became mad with power and began to control and spawns evil demons from himself in order to encase and rule earth with his evil.
The two boys realized that he become a greater threat to all the life on earth, they begun to search him, when they met him he was consuming a girl to fed himself, the two tried to defeat him but they failed.
Jukokubo later took the form of a human to separate the brothers and kill Ryoi, however his plan failed and began to transform Aimi into a demon in order to use her as a distraction, in the end he was stopped and confronted by Hyoi who managed to kill him thanks to the sacrifice of two students.