Masumi asks Ran if she can come over to talk to Conan. Once there, she learns Conan is at Agasa's with the Detective Boys and the fact Conan is with Kogoro on every case. They are soon interrupted when a gunman strapped with bombs and three hostages are brought into the agency. The gunman, Isao Sawaguri, demands Kogoro to determine which of his three hostages killed his sister. Conan calls Ran to ask who she was spotted walking with. Masumi answers and pretends to end the call, allowing Conan to eavesdrop on the situation. Conan learns the case of Sawaguri's sister, Miku Sawaguri, was concluded to be suicide when she was found with her wrist slit inside her locked ryokan room. Agasa and the Detective Boys leave to interview the local neighborhood association who were at the ryokan during Miku's death. Conan gradually learns more about the case from information spoken by Sawaguri, the media, and the Detective Boys.