Chikai Kuji
About
Age: 25
Birthday: 9 December
Blood type: O
Toi's yakuza older brother. His worldview and actions are guided his ardent belief in the survival of the fittest, as demonstrated by his willingness to dispose of anyone he perceives as weak.
This included Enta even after he helped him escape the police by kicking him in the path of a yakuza member charging at him with a sword. It also extended to his younger brother Toi even after he demonstrated great strength by shooting at the thugs targeting his brother and saving him.
(Source: Wikipedia, Sarazanmai Wiki)