The characters from Ranma 1/2, Urusei Yatsura, and Inuyasha all gather together in a short crossover to introduce the 50th Anniversary Weekly Shonen Sunday "Rumic World" Museum opening, celebrating Rumiko Takahashi's manga work.

As the perpetually lecherous Ataru and his friends prepare for a carnival at Tomobiki High School, they gradually realize the days are literally repeating themselves. Any effort to break the pattern dumps them back where they started.

It is summertime, and Shinobu laments not having a boyfriend. She then happens upon a young man weak from hunger, and wearing a rabbit costume. She gives him a carrot, he expresses his gratitude by hitting on her... and she hits back. The young man leaves behind a key to another dimension where everybody's possible futures exist. Lum and Ataru join Shinobu to find the bunny boy, and happy futures for themselves.

Ataru and the others will join the competition of 'The Obstacle Course Swim Meet', organized by Tomobiki High Principal and Onsen-Mark. Each of Tomobiki High students need to face different kinds of obstacles during the competition, only few of them reach the finalist and their situation is getting harder and harder than previous obstacles.

A mischievous spirit gives Ran a heart-shaped candy that causes a magical heart to appear over the head of whoever eats it. And whoever catches that heart captures the heart of the person who ate the candy! And if there's one thing the Urusei Yatsura crowd can do, it's play catch!

Mendou recounts an old story that warns, “Don’t take pictures in front of the statue of Great-Grandfather’s Goat, or terrible things will happen!” When his father does just that, only Sakura and Onsen-mark the Teacher can ward off the horrifying consequences of an ancient family curse… or can they?

Ataru learns to think before he eats when he gobbles down some of Lum's Cherry Rice Cakes -- and promptly starts turning into a wolf!

Six-year-old Ataru steps on Elle's shadow during an impromptu game of shadow-tag; in Elle's culture, this is viewed as a marriage proposal. Eleven years later, Elle returns to Earth in order to marry Ataru — by which time not only had he forgotten the events of his childhood, but he was also going out with Lum. The rest of the plot focuses on Lum's attempts to prevent the marriage. The film was directed by Mamoru Oshii who was mad at the many requests that the producer made of him to alter the movie. Rumiko Takahashi considers this film her favorite and it is the most true to the original series.

Mendou hires a new personal Ninja with some very unusual abilities, only to have him fall head-over-heels for his manipulative sister, Ryoko.

It seems that Lum's grandfather made an agreement that should he have a daughter, she would be married to a traveling merchant that he met. Now, the merchant has come to collect due. Ataru is tricked into thinking that Lum wants to leave, and so, in a moment of anger, says he hates her. Arguments erupt, and Lum decides that she must know the truth of Atarus feelings. As for all the questions of importance for the Onis, a game of tag begins, one that Ataru can win simply by telling Lum I Love You. However, in the end his pride may end up dooming him. So begins the series of events that will at long last decide the future and fate of Ataru and Lum.

Lum, Ataru, Mendou and Shinobu visit an inn which Ryuunosuke and her father have opened. But when it turns out to be on a haunted desert island, the stage is set for some serious silliness!

While performing in a student film, Ataru cuts down Tarozakura, a large, ancient cherry tree. Strange things begin to happen all across Tomobiki: a mountain appears out of nowhere, spring changes to winter, and Lum loses her powers, while those around her act as if she doesn't exist.

Ten gives Ataru an alien disease, the contagious "Girl Measles," (which makes the victim's eyes turn big and twinkly, like the eyes of young girls in much of manga and anime), and when Ataru's girl-hunting spreads the virus all over Tomobiki Town, chaos ensues!

Lum & her girlfriends are invited to Neptune by Oyuki. There she shows them her new business venture at a ranch of flying sherbets, birds capable of producing sherbet cones from their beaks. Ran convinces Oyuki to let her borrow one, her goal is to make some quick cash selling sherbets on Earth. Unfortunately, the combination of being overworked and a hot summer day has made the sherbet extremely cranky, even from its refrigerated cage. It breaks from its cage and escapes, but not before attacking Ran and Lum, and trashing Benten's brand-new bike by shooting sherbet cones at it. Now it's up to Ran to retrieve the sherbet before Benten blasts it out of the sky, and more importantly, before Oyuki finds out.

Ryoko throws a tea party for her friends. Flashbacks reveal the pasts of Ryoko's various guests.

Lupika, an alien princess, is in love with a tofu seller. To make him love her too (at least, announce his love. He obviously fears the social taboo of a tofu vendor marrying a princess), she needs to get a love potion, which is in a certain temple. Legend has it that the only person that can obtain this love potion is the most lecherous man in the universe. That man turns out to be Ataru Moroboshi. Lupika kidnaps Ataru to make him get the potion, and Lum and her friends go out to search for Ataru.

The third film finds Ataru transformed into a pink hippopotamus, which sends Lum chasing after the wicked magician responsible, with catastrophic results. With Lum gone, her friends decide that there is no reason to remain, and so Tomobiki slowly returns to normal. The highlight of the film is a high speed chase scene with an angry Lum flying after the mysterious Ruu through the city at night and into a hall of mirrors (and illusion ). Ataru's true feelings for Lum are probably more obvious in this film than any of the others.

Featured special that uses scenes from the series stored on a personal satellite of the Los Mendo family.

When Tsubame tries to go on a date with Sakura, the ghost of a young girl decides to go along - as his girlfriend.