It seems that when Lum was born, a postal screwup resulted in a witchy friend of the family not getting an invitation to the celebration. The witch put a curse on Lum, that she would never be happy with her True Love. 

In the present, a new Amusement Park has been built in Tomobiki, and opening day finds the whole gang sampling its pleasures. At a magic show, however, Ataru gets turned into a large pink hippo-potamus, FOR REAL! 

When Lum attempts to track down the magician that transformed her Darling, things start to get very weird, very fast! 

(Source: AniDB)

Strange things begin happening in Tomobiki Town... 

When a great cherry tree, "Tarozakura" is cut down while Lum & Co. are making a movie, Lum loses her horns-and her powers! Thus begins the strangest and most lyrical of the Urusei Yatsura movies...

(Source: AniDB)

The adventures of Lum, Ataru, Ten, and all the gang from Tomobiki continue in an assortment of new – but no less weird – stories. Watch as Lum, Ataru, and Shinobu encounter a rabbit-clad youth, enter the Room of Destiny, and get a glimpse into their futures in "Inaba the Dreammaker," or see Ran's plans to use a sherbet cone-producing bird to open a sherbet shop one hot Tokyo summer go terribly awry in “Raging Sherbet.” Ataru has yet another bad experience with Lum's cooking in "I Howl at the Moon".

Touka Gettan is set in the land of Kamitsumihara, where traces of magic and legend can still be seen. The land has been under the protection of the Kamiazuma clan since it was founded. The story revolves around Touka Kamiazuma, the main protagonist, and his encounter with a young girl named Momoka Kawakabe who comes to stay with the clan. Their meeting sets off a chain of events that will bring an ancient legend to life.