Ranma ½, part 5 number 8

The cover has Ranma-chan and Akane holding P-Chan, duck-Mousse, and neko-Shampoo.

Part 15: The Happiest Mousse: Mouse and Ranma are having another fight and, as always, Mousse uses lots of hidden weapons (showing, as far as martial arts goes, that he is without honor since he's fighting an unarmed man). In the end Mousse loses.

Part 16: Tsubasa Kurenai Busts Loose!: Ranma is attacked by a mailbox. At least it appears to be a mailbox, but it's really Tsubasa, a guy who dresses all the time as a girl. Tsubasa had fallen for Ukyo at their last school and has followed Ukyo since. Akane tears open Ukyo's blouse to prove she's really a girl, but Tsubasa says she/he knows that.