Nanaka acts coldly towards Sana the following day, even after Sana explains his incident with Asami was an accident. After Sana exclaims that Nanaka is not her old self, she angrily runs away. Sana comes upon an old mailbox that Sana and Nanaka used for private communication in their youth, and finds dozens of letters, some desperate cries for help. Sana then learns from Shusuke that three years earlier, Nanaka's house had burned down, killing both of her parents and traumatizing her...