Ranma ½: Season 1, Episode 10 - ProjectFreeTV

1 - 10: P-P-P-Chan! He's Good For Nothin'

Not knowing that it's Ryoga, Akane adopts the little black pig as her pet, naming him P-Chan. This of course drives Ranma crazy, as he desperately wants to get Ryoga away from her, yet feels honorbound not to reveal the secret.