Urino has a plan to catch the arsonist in the act.

Urino's rules spark escalating arson; Hiyori supports him while Osanai gives advice as bonds shift.

Kobato explains to Osanai how he arrived at his conclusion about the arsonist’s identity.

Kobato wakes up in the hospital and sees a box of chocolates with a message from Osanai.

Kobato and Osanai finally find out the whole truth and get help from an old acquaintance.