The Defense Four are assigned as the JNR idol Noa Kashima's guards during a performance on the beach. After guarding her from a fan at the station, Takayama faints. As thanks, Kashima gives him her stamp collection book. During a practice session, flash paper is burnt as a threat to Kashima's performance. The following day, during the performance, the criminal, disguised as a member of staff, attempts to run on stage and stab Kashima...