Yamashita Kenzo (山下 健蔵, Yamashita Kenzō; "Kenzo Yamashita") is Yamashita Kazuo's eldest son and the shadow boss of Under Mount Inc. unbeknownst to the majority of the world.


Kenzo has a decidedly androgynous appearance with a long hairless face, long black hair that falls past his neck and is styled with a middle parting, cold dead-looking eyes, a thin nose, full lips and finally a pair of rectangular semi-rimless glasses; his overall facial expression conveys a cold calculating feeling. Because Kenzo spends all of his time inside his room, he typically only wears a shirt and dark pants.


Kenzo is an extremely calculating and methodological person who cares not for the recognition of others but is content with ruling from the shadows; to that end, he does not trust anyone and even modded his house into a fortress over the time he had shut himself in without his family finding out.[2] He can be described as a high-functioning hikikomori, due to not leaving his house in a decade; he stops his hikikomori tendencies after his encounter with the Kure Clan.[3] Similar to Hanafusa Hajime, he has no qualms about going to unethical extremes for scientific advancement, like trying to grow a brain from rat neurons.[4]


Kengan Ashura

Having watched Tokita Ohma's Kengan Association membership challenge match via Ohta Masahiko, he was surprised by the presence of his father in the audience. Having been aware of his father being a Kengan Association member and the upcoming Kengan Annihilation Tournament, Kenzo informed Ohta that they would be hiring someone from the Kure Clan to represent them in the tournament.

On the opening day of the tournament, Kenzo was seen viewing the events from inside the sanctity of his room.

Right before Under Mount's second round match in the tournament, Kenzo realised he was being targeted by the Kure. With them setting of a detonation, he activated security measures around the house and hunkered down as the Kure began their attack. While the fight was ongoing, the Kure managed to breach and subdue Kenzo, however he was ultimately spared after Ohma defeated Raian.

After the attack, he (and his brother Yasuo) flew to Ganryu Island, where the tournament was being held. After the second round had closed and the after-round celebration was ongoing, he encountered his father with the two catching up and Kenzo even agreeing to settle his father's debts.

After the end of the Kengan Annihilation Tournament, Kenzo, now an ex-hikikomori, instructs Ohta to setup a meeting between he and Bando Yohei.

Kengan Omega

Not long after the events of the Kengan Annihilation Tournament, Kenzo visited Bando Yohei in prison and gleaned from him that he had also received sponsorship from an unknown party in exchange for information on his brain-related research.[5]

Kenzo visited his father and warned him that he may have broken a taboo by trying to have a DNA test done on Tokita Ohma. Revealing a mysterious individual swiping Kazuo's package on a CCTV recording three months prior, Kenzo then informed Kazuo about the Worm, and how they were Under Mount's secret sponsor of Kenzo's research all the way up until the recent Kengan Annihilation Tournament. Adding that they had also worked with Bando, Kenzo warned his father that it seemed Worm were trying to build something and to be careful.

Power & Abilities

Kenzo is remarkably intelligent, being able to read scientific articles from a young age[4] and, in his adult life, run a successful corporation from his room for ten years using a proxy CEO to do things for him on the outside.[6]

Notes & Trivia

  • His surname "Yamashita" (山下) literally translates to "under the mountain", meaning that his company, Under Mount Inc. (アンダーマウント社, Andāmaunto-sha), was named after himself.
  • Kenzo has dreams of creating a true "IT society". To that end, he has dedicated his research towards creating a "cyberbrain" (a form of technology that would link humans with machines).[5]



Community content is available under CC-BY-SA unless otherwise noted.