Shiratori has Takagi search for the drinks at the theater and to bring them to the apartment. Shiratori reveals his deductions and explains that Kasakura drugged him with sleeping pills and placed her tuque on him to create her alibi by having Shiratori impersonate her. Takagi arrives at the department and shows them Shiratori's drink. Shiratori reveals that he had broken a piece from the flower design yet all the pieces remained on his drink revealing that Kasakura switched his drink while he was asleep to hide the fact there were sleeping pills in them. As further evidence, Shiratori explains that there was a white string on his head from the tuque meaning his hair should also be found on Kasakura's tuque. Kasakura confesses and reveals that her boyfriend had been cheating on her for the past two years and she killed him in vengeance.