Ranma 1/2 OVA 1: Shampoo's Sudden Switch - The Curse of the Contrary Jewel

"Oh, Cursed Tunnel of Lost Love! Let My Love Be Forever"

Shampoo discovers a broach which makes her feel the opposite of her true feelings for Ranma. Ranma begins to panic at the thought of losing one of his fiancees, and plans to tell Shampoo that he loves her.