Gin is tricked into turning up to a reunion party with Katsura and Sakamoto. The two are unhappy with their lack of screen time and are determined to start a flashback arc, but they then get sidetracked trying to figure out the identity of a supposed fifth hero who supported them from the sidelines.

Gin and co finally remember the phantom fifth member, Kurokono Tasuke. They also remember blowing him up by accident! Could it be that this reunion was arranged by Kurokono's vengeful spirit?