One day Ryoga Hibiki, a super-strong martial artist with an obvious grudge against Ranma, appears at school to challenge Ranma. Ryoga-who can't find his way around his own backyard-quickly gets lost, and the truth behind Ryoga's grudge is revealed.

The P is for pig, and the chan is for little. When a tiny pig roams into the Tendo's life, Akane latches onto it as a pet, naming him "P-chan." She sleeps with P-chan at night and protects him from an angry Ranma during the day. Ranma is the only person who knows P-chan's true identity.