The Revolving Sushi Mystery (Part 2) While investigating, Conan realizes Ryuuzou was left-handed and finds out how the murder was done. Using his voice changing bowtie, Conan impersonates Agasa and reveals the wet wipe contained the poison. Since the wet wipe was left of Ryuuzou, the only one capable of switching Ryuuzou's wet wipe with a poisoned one is Osamu. Conan reveals that during the mass panic due to the poisoning, Osamu used an old sushi plate and put the poisoned wet wipe onto the conveyor belt. The scanner on the conveyor belt sensed the plate was old and pushed the plate into the trash. After finding the wet nap in the trash, Osamu confesses to his crimes and reveals that Ryuuzou posted insulting comments onto Osamu's food blog causing him to go into a depression and therefore caused his wife to leave him.