Urusei Yatsura - Season 1 Episode 45 Big Springtime Picnic Uproar! (1) Grab her horns and she might just become your darling!
Overview: On a class field trip, Ataru journeys to an underwater kingdom; and Ataru, Lum, Shinobu and Mendou get lost in a cave (exposing Mendou's legendary fear of the dark).