Meitantei Conan › Season 1

Chapter 6 — Valentine Murder Case

Ran is invited to attend a Valentine's party by Minagawa Katsuhiko and Conan, obviously jealous, follows her. During the party, they meet Katsuhiko's family, Mrs. Minagawa, his little brother Minagawa Susumu, and his tennis club members Wakamatsu Toshihide, Sekiya Kaori, Naomichi, and Watanabe Yoshimi. Dinner is served along with cake and coffee. Katsuhiko, the party's host, drops dead from poison in the yard. Conan investigates and discovers that Katsuhiko was poisoned from the coffee served. Conan uses his newly acquired tranquilizer dart wristwatch to knock out Kogoro and uses his voice changing bow-tie to impersonate his voice. Through Kogoro, Conan reveals that Mrs. Minagawa murdered Katsuhiko; she put poison in the coffee served to everyone. The antidote for the poison was contained in the cake that was eaten by everyone, except for Keenan. Mrs. Minagawa reveals she needed the money in order to save the family house after her husband's business failed. Later, Ran holding a box of chocolate for Shinichi and decides to eat it with Conan. (Source: Wikipedia)