Different Dimension Switch - Where is Darling!? Urusei yatsura : Season 1 Episode 130

During Hanami, Ataru snaps a tree branch and somehow causes a rip in dimensions, sending Lum to a parallel world. Here Ataru lost the game of tag in the first episode, his family living in poverty. And he refuses to talk to Lum because he is upset that she ruined his life, as well as his parents'. Lum hops dimensions in hopes of finding the real Ataru.