Case Closed (1996)

Season 6

Episode 7: The Night Before the Wedding Locked Room Case (Part 1)

Heiji and Kazuha visit Tokyo accompanied by Mouri, Ran, and Conan. They run into Heiji's father's friend and are invited to their mansion. There a murder occurs and his father's friend is found dead in a locked room. It seems he was dragged to another room after being stabbed in the heart.