Jun

Jun is a professional martial artist who extorted delinquents with two of his friends. His crime spree was ended by Tsurumaki Yoshiki, who defeated him to avenge Rakuzaki Kai.

Plot
Jun is introduced towards the end of Chapter 80, beating and stealing money from members of SID. His two friends, one being his cousin, nervously tell him that what he is doing is dangerous. Jun assures them that delinquents will not report them to the police and that he will leave town the next day.

Later that night, the trio accosts Rakuzaki Kai while he is alone buying drinks from a vending machine. Jun beats Kai, dislocating his left shoulder, and forces him to lead them to Tsurumaki Yoshiki and Iguchi Tatsuya. When they meet, Jun asks for them to peacefully forfeit their wallets, but Yoshiki steps in to defend Kai and Tatsuya.

They move their fight underneath a bridge, where the terrain is more even and there will be fewer interruptions. Tatsuya deduces that Jun has a background in martial arts and can pose a challenge for Yoshiki, who is already injured, so he silently decides to jump in if necessary. Jun's cousin warns him that Yoshiki was previously the Head of Kilihito, but Jun is excited at the prospect of facing a strong opponent and rushes Yoshiki. In response, Yoshiki effortlessly knees Jun in the face, breaking his nose, and puts him in a headlock until he goes limp. The others watch in awe as Yoshiki lays Jun's body on the ground. To their horror, Yoshiki grabs a boulder to crush Jun with, but drops it when Tatsuya tackles him. The boulder lands on Jun's knee, breaking his leg brutally. As Tatsuya unsuccessfully tries to restrain Yoshiki, Kai repeatedly punches Jun, thanking Yoshiki for avenging him.

It is later revealed by Atsushi Tanzawa that Jun was permanently crippled by the injury.