Ranma 1/2, Volume 17

An amnesiac Kuno challenges Ranma to a duel at the beach -- wearing a watermelon on his head! Will another watermelon on the head bring his memory back? Or will Ranma's meddling unleash a fate more terrible than he can imagine? Meanwhile, a special sauce makes Ranma sick, and Ranma learns that to prove they're a loving couple, he and Akane must spend the night in the same room!