A series of murders occurred in Japan, resulting in the deaths of two police officers. Several days later, during a wedding celebration hosted by Shiratori Saro, the sister of Officer Shiratori, an incident unfolded. While attending the event, Ran and Officer Sato were attacked in the restroom. Officer Sato sustained multiple gunshot wounds, leaving her critically injured. Although Ran unintentionally caught a glimpse of the assailant's face, the traumatic experience caused her to lose her memory.