Sonoko, Ran, and Conan once again meet up with Eisuke. They go to a karaoke spot. On their way there, they are followed by a man with hat and sunglasses. Later, this same man turns up dead at the spot, and Conan finds Eisuke to very suspicious. Is it possible he had something to do with the murder?

A child asks the Detective Boys for help on investigating someone who is doing something weird. They are told to come by tomorrow. The next the kid's apartment has been burned down. The only clue to the culprit is the kids Diary, mentioning the Yellow guy who argued with the kid's father. Now Conan must solve this mystery while Sherry senses a black organization member nearby.