Urusei Yatsura: The Final Chapter is the fifth movie tie-in released for the 1981 Animated Adaptation of Urusei Yatsura. Unique amongst the six movies, it is the only one to not be a Non-Serial Movie, being instead an Animated Adaptation of the World of Darkness Arc, the 11-chapter long arc that served as the grand finale of the manga.
In The Final Chapter, Lum discovers that her great-grandfather made an enemy of an alien named Uba 120 years ago, who has vowed to claim the first girl-child to be born into her family. Being too old to marry her himself, he instead desires to force Lum into wedlock with his own great-grandson, Rupa. When Lum refuses, he and Rupa kidnap her and spirit her away to their planet, the World of Darkness. Ataru comes to her rescue, along with Shutaro Mendo, Oyuki, Benten, Ran and Rei, but in the chaos and confusion as the wedding reception is attacked by Rupa's insanely jealous would-be wife Carla, Lum and Ataru suffer a catastrophic case of miscommunication. So hurt is Lum that she decides to challenge Ataru to a second 10-day game of tag; if he fails to either catch her or tell her that he loves her before the 10th day, then Lum will erase the memories of aliens existing from everybody in Tomobiki!
This movie includes examples of:
- Adaptation Expansion: Whilst very close to the manga, the film does include some unique material:
- Lum tries to hide that she's crying after her and Ataru's videophone argument by swimming in the glowing lake.
- An extended battle between Mendo's forces and the memory-erasing device.
- Benten gets angry at Lum when Lum reveals she's going to remove the Earthlings' memories of aliens, as she's grown fond of her human friends, and threatens to end her friendship with Lum if she goes through with it.
- Lum and Ataru's final showdown taking place atop the ruined Tomobiki High School, and the angry denizens of Tomobiki chasing Ataru and Lum in the final seconds of the movie.
- Chased Off into the Sunset: The film ends not with Ataru and Lum running off to school, as in the manga, but with the entirety of Tomobiki chasing after them with the intent of beating them up after Lum concedes victory to Ataru without Ataru having professed his love to her.
- Childhood Friend Romance: Rupa and Carla were friends when they were kids, and that's when Carla fell in love with him. Even though she went mad with jealousy after they learned of his "Arranged Marriage" to Lum, Rupa retained feelings for her, and they ultimately do hook up.
- Clingy Jealous Girl: Carla is this at her best.
- Invoked by Ataru at the start of the tag match; it's when he realizes he can't lure Lum into grabbing reach by hitting on girls that it really sinks in how serious she is about this game.
- Determinator: When Ataru sets his mind on something, he will not give up. Whether that "something" is saving Lum from Rupa, or catching her in the game of tag.
- Detrimental Determination: It's called out that both Ataru and Lum share the common flaw of being far too stubborn for their own good. Ataru's refusal to just say "I love you" to Lum and instead try to catch her himself is the most obvious one, but Benten also calls out Lum repeatedly on how she's being stubborn and unrealistic in her demands.
- Disposable Fiancé: Rupa, Lum's "fiance" is introduced in this movie, and by the end of it has given up on her. Downplayed in that Rupa has no real reason to want Lum, as they had literally never met before Uba ordered Rupa to kidnap her and Lum is quite adamant at wanting to be with someone else. It certainly doesn't help either of them want to pursue the engagement that it was all Uba's petty scheme.
- Dogged Nice Guy: Whilst he does kidnap her, Rupa otherwise treats Lum patiently and with respect, and ultimately agrees to annul the engagement when he sees how unhappy it makes her.
- Double Standard: Abuse, Female on Male: Nobody ever gives Rupa any credit for being unhappy with Carla's constant and extremely violent attacks against him, nor admit he has a reason to be uninterested in her romantically given how insane she acts.
- Drama Bomb Finale: A series defined as an episodic comedy canonically ends with our heroine Lum being kidnapped, which in turn leads to her and Ataru having the single worst fight of the series, to the point that Lum challenges Ataru to either tell her that he loves her or she'll leave the planet, order her alien friends to go with her, and wipe everybody's memories of the aliens. And it really looks like Ataru is going to lose, to the point that their alien and human friends start saying tearful farewells to each other.
- Easily Forgiven: Rupa decides to just forgive ten years of Carla attacking him like a lunatic and instead marry her after giving up on Lum.
- Averted with Ataru; he has to work damn hard to make Lum realize he genuinely does love her and thus agree to stay with him.
- Evil Old Folks: Uba may be a Non-Action Big Bad, but he is directly responsible for everything in this movie. He started the whole mess by demanding a bride, and then tried to force Lum and Rupa to get married. He caused Lum and Ataru to break up by using the copying mushroom to create a clone that Ataru mistook for the real thing.
- Hidden Depths: Ataru doesn't want to tell Lum "I love you" to win the game of tag... because he doesn't want her wondering afterwards if he just said it to win instead of meaning it. Even though everybody else is encouraging him to just lie to her, it means too much to him that Lum knows that if he said it, he meant it.
- If I Can't Have You…: Whilst preparing to break into the wedding hall and disrupt Rupa's wedding to Lum, Carla vows to kill him and Lum. Shortly afterwards, when Rupa declares he doesn't love Carla, she screams that she'll kill him and then herself before blazing away with her gun.
- The "I Love You" Stigma: The big drama of the second half of the movie; Lum demands Ataru say "I love you" or she'll break up with him in the most terminal way plossible. But Ataru doesn't want to say "I love you", at least not under circumstances like this.
- Ladykiller in Love: The fact that Ataru actually does love Lum, as opposed to simply lusting after her like he does all the pretty girls, is shown to be why he won't take the easy way out and just say "I love you" to her — it means too much to him that she knows he meant what he said, as opposed to suspecting he just lied to make his life easier.
- Memento MacGuffin: Rupa kidnaps Lum by using a ring with a special mushroom in it to make her horns fall off. Ataru finds these just before Rupa flies off to his ship, and is shown keeping them tight throughout the story. It's when Ataru drops these at the climactic moments of the final match that Lum realizes that Ataru really does love her, even without him saying the words, causing her to forgive him, forfeit the match, and re-affirm their engagement.
- Murder the Hypotenuse: When Carla goes to attack Rupa's wedding to Lum, she makes it very clear she would prefer to kill Lum so she can take Rupga for herself.
- Poison and Cure Gambit: Uba used a variant on Lum's nameless great-grandfather 120 years ago; he offered the starving oni two mushrooms, with one being food and the other poisonous. When the oni picked the poison mushroom, Uba demanded his daughter's hand in marriage as payment for the antidote. But once the oni was cured, he gloated that he had no daughters, so Uba vowed he would claim his first female descendant instead.
- Poor Communication Kills: The big game of tag is kicked off when, during Ataru and Carla's attack on Rupa & Lum's wedding, Carla creates a distraction that lets Uba and Rupa swap out the real Lum for an obedient clone made from a mushroom. This clone tells Ataru to go away, because she wants to marry Rupa. When Rupa is making a climactic getaway with Lum and Lum screams for Ataru to save her, Ataru is so convinced it was the real Lum who said that to him that he turns away from her. Even though Ataru does save her when she falls off the roof shortly afterward, their feelings are so hurt that they start arguing, which ultimately leads to them both breaking off their "engagement", which in turn builds to Lum declaring the game of tag to see if Ataru really did love her.
- Ship Tease: Benten angrily threatens to end her friendship with Lum if she wipes the humans' memories of aliens, as she's grown fond of her "friends". The only human she's had several friendly interactions with enough to be friends with is Ryunnosuke, suggesting Benten feels so strongly for Ryunnosuke she'd end her longest friendship (with Lum) over losing Ryunnosuke.
- Stalker with a Crush: When not attacking Rupa with heavy weaponry, Carla would shower him with all kinds of presents bearing her likeness.
- Unwitting Instigator of Doom: Unlike in the manga version, Carla didn't mean to bring the giant mushrooms from the World of Darkness to Earth, and it was Ran who caused them to start taking over the city by dropping them in the soup whilst trying to feed them to Rei.
- Woman Scorned: Carla began a decade-long campaign of constant harassment against Rupa after he declared he was in an Arranged Marriage with Lum.
- Yandere: Carla loves Rupa. She loves him so much she would rather kill him and then kill herself before she'd let him marry another girl.
