Kenji Asai
The brother of a low-level yakuza boss, kenji is extremely skilled at hand-to-hand combat. kenji is even able to go hand-to-hand with the aeons. while he initially appears to be a sociopath, killing both soldiers and non-combatants without any signs of remorse, flashbacks in the fourth volume show him to be a psychologically complex character who is driven by basic human needs such as love and meaning.