Mitsuhiko Tsuburaya lends Conan Edogawa a massive amount of manga, which Conan starts reading, despite the overwhelming quantity. Elsewhere, Kogorou Mouri is asked by the Mine family to protect the treasured sword in their dojo, as Kaitou Kid has sent a note of his intent to steal it. Upon arriving at the dojo, Conan and the others meet Yaiba Kurogane. Together, they aim to thwart the phantom thief's plans. However, Conan begins to notice something strange about the case.

A murder occurs in a retro hotel room at Dolphinland. Why is there an ice cream bar, candies, pepper spray and a coin-operated television in the room?