Ein

Ein (アイン) is Asuka's father who chose to make ends meet as a bounty hunter to provide for her. One day, Ein is hired by Jako to kill Kenshiro. Although Ein threatens to take his life, Kenshiro senses Ein's caring and benign nature and refuses to fight him. When Asuka is kidnapped and held ransom for the job, Ein thinks he has no choice but to kill Kenshiro.

Bat heard of Ein's past and convinces the bounty hunter to forsake his profession. He challenged Ein to become a self-made man who Asuka would be proud to have as her father, offering him a position in the Hokuto army. When his betrayal is reported back to the Celestial Emperor army, Kenshiro defeats Asuka's kidnappers and rescues her for Ein. Thankful for the act, Ein joins Bat and Rin's raid of the Celestial Emperor's main keep. Jako opens a pitfall for them to where Rin is reunited with her long lost sister. Falling boulders and the rushing groundwater threatens to drown them.

A giant boulder blocks their escape, and Ein is the only one with the power to break it. He uses every fiber of his being to punch through it, saving everyone inside but severely weakening himself. He succumbs to his wounds and perishes. His corpse is brought to Asuka. She gives her father's gloves to Kenshiro as a keepsake.

Fighting Style
Kenka Kenpo is boxing-like style which relies solely on the user's fists. It has the power to smash through rocks and boulders with ease. Ein brags that he has killed many people with his fists alone.