Chapter 17

Living out of a battered tent with his pet Piisuke, Heisuke dreams that collecting the bounty on Sakamoto will end their poverty and even buy them sushi. He shuffles into the shop demanding Sakamoto be handed over, not realizing the clerk in front of him is the target. Sakamoto plays dumb, insisting he only works there, while Shin marvels that reading such an idiot's mind is a waste of effort. After sobbing about his empty wallet, Heisuke is handed pork buns by Lu and Shin and shuffles back out.

Outside, a gust rips away his tent just as an airsoft tournament flyer slaps across his face, its one million yen prize promising the apartment he craves. He signs up but learns solo players are barred, so he begs Shin and Sakamoto, who happen to be entering to win prize money for shop repairs, to let him join their squad. The three register together.

Once the match starts, Heisuke blindly guns down rival teams while Shin and Sakamoto dodge and counter with ease, carrying the group toward victory. Growing suspicious of his teammates' skill, Heisuke asks if they are airsoft fanatics, then vows to charge ahead and trust them to cover him. A tipsy Lu nearly blurts Sakamoto's identity before Shin hushes her, and the trio laughs it off until Heisuke finally pieces it together and swings his rifle straight at Sakamoto.

Heisuke Mashimo and his pet Piisuke debut, introduced as a penniless would-be assassin chasing Sakamoto's bounty. Heisuke fails entirely to recognize Sakamoto despite standing before him and accepting his charity. A windblown flyer draws Heisuke into a local airsoft tournament, the same event Sakamoto's crew enters for repair money. The three form a team and dominate, before Heisuke belatedly realizes his ally is the very man he came to kill.

Titled Heisuke Mashimo (Mashimo Heisuke), this is the seventeenth chapter of the series and part of the Lab Arc. It ran in issue 17 of 2021 on March 29, 2021, and is collected in Volume 3. The chapter marks the debut of both Heisuke Mashimo and Piisuke, and leans heavily on comedy built around Heisuke's cluelessness.