Urusei Yatsura S01 E23 Love Battle Royale

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

First appearance of Tsubame, Sakura's boy friend who has some magic abilities. Sakura invites Ataru, Lum, Shinobu, Megane, Perm, Chibi, and Kakugari to a disco. Things later go haywire as Tsubame starts casting spells and all sorts of weird creatures appear, including Rei.