Ranma 1/2, Volume 10

Whenever male martial artist Ranma gets splashed with cold water he becomes a buxom young girl! Now, Ranma's arch-rival Ryoga has discovered how to reverse the transformation. But before Ranma can learn the secret, his strength is sapped by evil "sensei" Happosai. Is he doomed to spend his life being beaten up by infants and little old ladies?