Plot: Having regained her confidence after solving numerous cases together with Saruwatari (Maruyama Ryuhei), Sukui (Taira Yuna) has finally decided to return to her job as a police officer. At a celebration for her return, Sukui confides in Saruwatari that she wants to investigate the Yanaka Child Murders, the last unsolved case investigated by her father, Inukai Jūshiro (Yamaguchi Makiya), who died in the line of duty