Ataru turned into a hippo is the setup, but the real curse is watching Lum actually fight for something that matters to her instead of chasing him around for laughs. The second half drops the amusement park jokes and gets serious about whether these two can want each other instead of just orbit each other. By the end, the romantic stakes feel earned in a way the TV series barely touches.

When Lum was born, a mix-up with the mail meant a witch who was a friend of her family never received an invitation to the celebration, and in response the witch cursed Lum never to be happy with her True Love. Years later, a new amusement park opens in Tomobiki, and the whole gang turns out on its first day. During a magic show there, Ataru is changed into a huge pink hippopotamus, and the transformation is real. Lum sets out to track down the magician responsible for what happened to her Darling, and events quickly take a strange turn. The film mixes comedy, drama, romance and science fiction.