Shinji Shiba

Shinji Shiba (新波真次, Shiba Shinji) is the son of Taizen Shiba and participant in the Adult Tomodachi Game. He participates in the All Bet Game, the Friend Murder Game, and The Friendless Game.

Abilities
Shinji Shiba is hitman trained to kill, can easily defeat Shiho Sawaragi who can take down a tree with one kick(chapter 80), dodge the bullets in the Friend Murder Game, and his strength is described as "overwhelming" by Shiho Sawaragi herself

Etymology
Shinji means second son. His father changed his name from Shinichi (first son) to Shinji after finding someone more worthy to be his successor.