Haruki was recruited as the third member of Toy ☆ Gun Gun, but resigned before Hotaru joined. In the past, Haruki felt that Masamune only cared about beating Team Hoshishiro and getting back at Nagamasa, thus steps down from the team. Afterwards, Haruki feels as if he has been replaced by Hotaru and how he acted towards Masamune was unforgivable; however, Masamune kindly accepts him as the team's fourth member again.