Ranma vs. Mousse! To Lose Is To Win
Taiketsu Musu! Makeru ga Kachi
"Mousse calls out Ranma to battle. During training at Jusenkyo, he fell into the Yahzu-Nii-Chuan, or "Spring of Drowned Duck," and blames Ranma for his new transformation. Incidentally, Mousse intends to splash Akane with water from the Yahzu-Nii-Chuan! " (source)