Ran and Conan run into Sachiko, an acquaintance of Ran's, while shopping. She says she is buying steak for dinner with her lover who's visiting. Later Ran and Conan find that Sachiko is murdered. Everyone suspects Sachiko's lover, but only Sachiko's steak had been eaten and there were no prints besides Sachiko's found on any of the items on the table. It's later revealed that Sachiko's lover died in a tragic climbing accident, and every month on the 25th for the last year and a half she has honored his memory. The murderer is confronted by Takagi, Ran and Conan; he eventually admits to killing Sachiko for rejecting him.