Episode 9

Sui (Taira Yuna) tells Saruwatari Hibiki (Maruyama Ryuhei) that the perpetrator of the child murder case is someone the two of them had seen in a used bookstore in the past. However, Saruwatari, regretting having injured Sui, pushes away Sui's desperate pleas to resume the investigation. Unable to give up, Sui calls out to Ushio (Kajiwara Zen) and Hyotou (Yamura Rintaro), and the three of them reunite in Mikan's room and plan to infiltrate the Metropolitan Police Department in order to obtain the notebook left behind by Sui's late father, Inukai Jushiro (Yamaguchi Makiya).