Atalum

Atalum is the het ship between Ataru Moroboshi and Lum from the Urusei Yatsura fandom.

Canon
Ataru and Lum meet when the oni (the extraterrestrial race to which Lum belongs) decide to invade Earth. The oni laws require that the representative of their species (Lum) first face the representative of the planet to be invaded in a tag match. This representative is chosen at random by a computer and the choice falls on Ataru Moroboshi. If the human representative wins, the oni will give up the invasion and leave. Ataru initially has no intention of participating, but when he finds out that it's just a game of tag and that he has to challenge a beautiful girl, he agrees thinking that it will be easy and plans to use the competition as an excuse to touch Lum. When he sees her he is very impressed by her appearance, but this means little since Ataru is the horniest individual in the universe and therefore adores all beautiful girls. The competition will last ten days, but from the beginning Ataru discovers that it won't be as easy as he thought, since Lum is able to fly. In the following nine days the boy tries everything, but fails to catch the alien. The evening before the last day Ataru is now desperate and therefore his girlfriend Shinobu to motivate him tells him that if he can take Lum, she will marry him. This has the desired effect and Ataru devises a plan to take the beautiful oni: since the latter is wearing only a bikini, Ataru takes her bra and when she flies towards him to take it back, he takes the opportunity to touch her horns, winning the challenge. Euphoric Ataru exclaims that now he can finally get married, but since she can't know that he's referring to Shinobu, Lum believes that the boy is asking for her hand and accepts happily. Ataru tries to clear up the misunderstanding, but Lum doesn't listen to him. Shortly after the girl returns to her planet to be able to obtain permits to be able to live on Earth. A group of Ataru's schoolmates, who have fallen in love with the beautiful alien, kidnap the young Moroboshi to force him to send a signal that will make her return immediately. However, the students make a mistake and call a space taxi that takes everyone to Ataru's house. The ride comes at a steep price that Ataru and his classmates can't afford, so the aliens make up for it by attacking Earth's oil resources. The people blame Ataru and try to lynch him, but the boy is saved by the return of Lum who has completed the necessary procedures for his transfer. The girl is delighted to see her betrothed again, and immediately embraces him, then proposing to pay for the fare. In exchange, however, she wants the boy to agree to live with her. The young Moroboshi has no intention of it, which makes the oni cry, but in the end he understands that he has no choice but to give in to the blackmail. As soon as Ataru agrees to let her live in his house, the girl stops crying and pays the ride, jumping on Ataru again. Lum immediately shows a total and obsessive love towards Ataru, coming to follow him everywhere saying that "Husband and wife must always be together". Obviously Ataru is very annoyed by it, both because of Lum's intrusiveness, because Shinobu is logically not happy with Lum's presence, and furthermore she attracts the envy of his classmates. Lum often shows her affection for Ataru, hugging him, rubbing up against him, and fondling him with sweet names. Despite his lasciviousness, Ataru will never try to encourage Lum's behavior, nor will he give in to her attempts at seduction: probably because if he had sex with her, Lum would have every right to consider herself his wife. After a while, Rei, Lum's ex-boyfriend, arrives on Earth in an attempt to win her back and, having run into Shinobu, has her accompany him to Ataru's house. Seeing an opportunity to get rid of Lum, Ataru and Shinobu try to persuade her to go back to her house with Rei. Ataru tries to convince her that she would be happier than her by marrying a member of her kind, and Shinobu remarks on Rei's beauty, but Lum declares that she prefers Ataru's sweetness. To get Rei out of the way, Lum invents that Ataru has made her pregnant, incurring the wrath of Shinobu and Rei on him. In the end the second one challenges the earthling to a duel, for Lum. Ataru doesn't want to accept, but Lum points out that Rei will kill him immediately if he refuses, so he is forced to accept. Lum cheers for Ataru and is very happy when he wins unlike Shinobu who is convinced he can't do it. After the duel, the two girls compete for Ataru. Ataru keeps trying to rekindle his relationship with Shinobu and date other girls, and Lum punishes him by striking him with her thunderbolts (Lum also possesses the power of electrokinesis). Unable to take it any longer, the boy asks the bonze Sakurambo to find a way to neutralize Lum's powers. The bonze then creates a hair ribbon that will block the alien's powers. The boy then passes it off as a gift that he wants to give to Lum who accepts it very happy. However, when she fails to use her powers she worries about it and Ataru consoles her. Shortly after, however, they run into Shinobu and Lum boasts about the gift received from Ataru; Shinobu who has never had a gift from her ex-boyfriend gets angry and tries to rip the ribbon off her, but Ataru steps in to stop her. Shinobu believes that these are signs that Ataru has fallen in love with Lum and leaves in tears, even hitting him. Lum thinks the same thing, and is very happy. In the evening Lum can't go back to sleep on his flying saucer since she can't fly and tries to sleep with Ataru. The latter tries to take the tape away from her, but she doesn't want to and when she finally discovers all of her deception, she gets very angry and beats Ataru. Lum prepares a lollipop for Ataru and the latter eats it, unaware that the cuisine of the oni is very spicy and inedible for humans and to try to extinguish the burning he eats a magical dessert created by Sakurambo; the two combined foods cause Ataru to double: one of the two has the usual personality and is in love with Lum, the other is a judicious boy with a great desire to study in love with Shinobu. The fact that the Ataru with the original personality is the one in love with Lum could imply that all the less used traits of his being have merged into the double and that he now loves Lum more than Shinobu. This version of Ataru has no problem declaring himself Lum's boyfriend and declares that he always wants to be together with her to enjoy the joys of life. At one point he even says he doesn't want to go back to normal, so that while the other Ataru goes to school, he can have fun with Lum. The alien is very happy with what happened and believes that the real Ataru is the one in love with her (and in fact he is the one who kept the original personality). The Ataru in love with Lum, is so devoted to the beautiful oni that he decides to go and live with her on her planet, probably even officially marrying her, leaving behind his family, his world and everything he knows just for her. The boy seems really eager to leave, but his mother tries to bring the two halves together with the help of Sakurambo. Both Atarus oppose the reunion and both girls try to oppose it, and the Ataru in love with Lum invokes the help of the latter who tries to give it to him. In the end even if it is not shown how the two become one again with the behavior of before and the usual attitude towards Lum.

When Shutaro Mendo, the very rich heir of the Mendo Conglomerate, enrolls in Ataru's school, he soon becomes the darling of the girls and even Shinobu takes a fancy to him, while Lum from whom Mendo is attracted, is the only girl to ignore him while remaining faithful in Ataru. Later both Mendo and Ataru run for class leader and draw, so Shutaro challenges Ataru to a duel and he wins thanks to Lum. Lum then attempts to use a computer to gauge her compatibility with Ataru, but gives her inconclusive results, before telling her she is more compatible with Mendo. Dismayed by this result, Lum decides to carry out a more thorough examination, subjecting both Ataru and Shutaro to a series of bizarre tests. However, the two have basically identical characters (Mendo simply tries not to point it out due to his social position, but in reality he is a womanizer like the young Moroboshi), so she happily decides to stay with Ataru, much to Shutaro's dismay.

Fanon
Atalum is the most popular ship in Urusei Yatsura's fandom. It's rival of Atashino.

Fandom

 * FAN FICTION
 * Ataru/Lum on Fanfiction.net

Trivia

 * Lum was originally supposed to appear only at the beginning of Urusei Yatsura, but she gained such popularity with readers that Rumiko Takahashi decided to make her the co-star of the work. The same reason led Rumiko to use Lum as Ataru's final love interest instead of Shinobu.
 * The popularity of Atalum prompted Rumiko Takahashi to draw inspiration from it for the relationships of the protagonists of her later works, also giving them a love-hate relationship.