Ep. 23: Conan deduces Ichiro is the serial killer on the cruise ship after analyzing the crime scenes.

23

Conan investigates Gozo’s murder scene and suspects Takashi is being framed. When power fails, Ichiro is stabbed in the dark. Conan interrogates butler Kenji and searches for Takashi before using the sleep-enhancing watch on Kogoro. He reveals that the killer framed Takashi in both Gozo’s and Tatsuo’s deaths by manipulating evidence. Ichiro’s claim of a flashlight attack contradicts his blindness, proving he stabbed himself and committed the murders. Conan cites Ichiro’s habit of carrying bread as an eraser, noting a crumb found in Gozo’s blood. Ichiro confesses to killing his grandfather and uncle after Gozo rejected his marriage proposal to cousin Natsue. Takashi admits he intended revenge but chose love with Natsue instead.