Kogoro, Ran and Conan are invited as special guests to a wealthy company owner's daughter, Reika for her twenty fourth birthday. Though as the guests are about to leave, Reika, and the team of suitors following her throughout the party discover that their tires are flat. Not wanting to drive with a stranger, Reika stays at the mansion, along with the team of suitors, Kogoro, Ran, Conan, the caretaker and a gentleman to watch over everyone. Though things turn strange when Reika doesn't return from changing. In persuit of her, one of the suitor's is discovered drowned in the front fountain....why was he murdered?