Ran tricks her mother and father into going to the beach together. Kogoro, annoyed, leaves for the bathroom and returns with two girls named Kiwako Toda and Harumi Matsuzaki who invite the Mori family and Conan to lunch with the scuba diving club at the local college. Kiwako decides to go snorkeling alone and asks Kiwako to get her a towel during lunch. After a while, the group spots Kiwako drowning and rushes to save her. Drowning is the least of their worries because Kiwako was bitten by a snake. Ran is sure she saw an erabu sea snake, but everyone is confused when she claims she saw the snake with wings.