Oikawa is introduced along side Feather Pistol, after shooting Eiryo Ashihana and Masaru Saiga. He tells them both he was bored, and asks them to play a game with him. Oikawa tells Ashihana he could stop Grimaldi with just one bullet, and puts Feather Pistol's gun away. When Masaru tells him to shoot at him, Oikawa laughs and asks if he his challening him, Oikawa then draws Feather Pistol's gun and shoots. Masaru and Ashihana pull Grimaldi backwards avoding the incoming bullet, then charge forward knocking them all into the elevator shaft.