The Bujin (Kenuicho Yakuri) is a heroic ninja warrior.
The Bujin operates as an independent hero in Japan. He refused the invitation of Heroes Alliance to join their organisation, taking them to task for not stopping to assist civilians and deal with other aftermath of their super-battles.
Japanese hero SHELL informed the Bujin that he had originally becoming SHELL out of concern for civilian collateral damage of super battles - his own family were killed in just such a way. After this, the Bujin was willing to at least assist Heroes Alliance in pursuing and capturing the Baku. After both The Yamada and Bakuto Clan, as well as The Baku and Yuki Matsumuro, were defeated - The Bujin reached an agreement with the alliance, where he would continue to be independent in Japan but give assistance if he was ever needed (and they would also do the same.)
The Bujin is a highly skilled swordsman, martial artist and ninja.