Meitantei Conan S2004E13 - Sweetheart Is an Illusion of Spring

Ran and Conan run into Sachiko, an acquaintance of Ran's, while shopping. She says she is buying steak and wine for dinner with her lover who's visiting. Ran is impressed that Sachiko has someone she wants to cook for. The next day Ran and Conan find that Sachiko is murdered. Kogoro gets permission to take a look, since Sachiko was a friend of Ran.