Eine junge Schauspielerin wird bei ihrer privaten Verlobungsparty in ihrem Apartment mit einer schweren Stichverletzung in der Badewanne gefunden.
Kogoro is invited to Yoko's engagement--no, Yoko's friend's engagement with a famous actor. When Kogoro arrives, though, he is hit with a tennis racket by mistake! It turned out that Yoko's frind had been blackmailed by an unknown person, and had been very careful when opening doors since. While everyone is watching a video, Yoko's friend goes showering. After quite a time Conan realises that something must be wrong and goes into the bathroom to find Yoko's friend lying in the bathtub with her neck cut.
L'idole Yoko Okino invite Kogorō, Ran et Conan à une fête de fiançailles chez une amie à elle. Arrivé sur place, le détective apprend que l'amie en question vit sous la crainte d'un stalker. Plus tard dans la soirée, elle est retrouvée dans sa baignoire, égorgée mais consciente.
Kogoro riceve una lettera da Yoko che lo invita ad una festa di fidanzamento a casa della sua amica Kaoru. Oltre alla coppia, a Yoko e alla famiglia del detective, partecipano alla festa anche altre due star ed il manager. Durante la serata Kaoru viene trovata in fin di vita nella stanza da bagno
Kogoro será invitado por Yoko Okino para la fiesta de compromiso de una amiga suya, mientras celebran, la amiga de Yoko es encontrada degollada en el baño.
