Urusei Yatsura S01 E129 Deathmatch! Ataru VS Mendo Brigade!

"Grab her horns and she might just become your darling!"

Episode 2 of a 2-episode serial. Despite their best efforts, all of Lum's Stroomtroopers except Megane have been kidnapped. Ataru is saved from captivity by Mendou's little sister Ryoko, who gives him supplies and even a motorcycle to save Lum with.