- How 'bout it? You know who The Mole is. So I want you to tell us.
- "You want your revenge?"
- Nah, we don't want it. We need it. Just part of bein' a yakuza.
Kengo has his hair dyed brown and slicked back. He has multiple piercings in his left ear, including a helix piercing, orbital piercing, industrial piercing, and a silver hoop earlobe piercing. He wears a red striped dress shirt embroidered with floral patterns, a gold chain necklace, light gray slacks, and white oxfords.
Despite being relatively green, Kengo sees himself as a yakuza through-and-through.
At a cho-han parlor in the Champion District, Kengo and other Matsugane family members arrive on the scene to save Hamura and Ozaki from Yagami and Kaito. He utilizes an aerosol flamethrower on Kaito and also sets fire to the cho-han parlor. They successfully rescue Hamura and Kengo sets off a grenade in the building with Yagami and Kaito narrowly escaping.
Kojiro Ozaki leads a raid on Honmaruen when Hamura is taken there, which Kengo is a part of. He assists the others in setting fire to the place. Before they can safely escort Hamura out, the Mole kills multiple members before escaping, one victim being Mitsugu Matsugane. Following Matsugane's death and Hamura going into hiding, Kengo becomes the de facto leader of the Matsugane Family, and asks Toru Higashi to get Yagami to tell them who the Mole is. The two fight Kengo and convince him to help them take down the Mole rather than recklessly risk their lives.