Dimensional Switch, Where's Darling? (異次元空間ダーリンはどこだっちゃ!?, Ijigen Kuukan Daarin wa Doko Daccha!??) is the one hundred and seventh episode of the Urusei Yatsura anime series. It originally aired on 11 April 1984. Its opening theme is "Pajama Jama da!" and its ending theme is "Koi no Mebiusu".
Lum and Ataru go flower viewing in the park where Lum goes through a dimensional warp and Ataru goes missing. She tracks him down and arrives at various parallel worlds of Tomobiki-cho where she meets different Atarus – one of which lost the tag game to her, a perverted Ataru, and a gentle romantic Ataru.
It's flower viewing season and Lum and Ataru visit the park together. Everyone around them are overjoyed and some are even dancing around. The pair make their way through the falling Cherry blossom petals, Lum holding on to Ataru's hands. As they walk, she takes a look around to see all the laughs and celebration around them and abruptly pulls Ataru to a stop. She tells Ataru that for some reason she's feeling insecure and asks Ataru to never leave her side. However, Ataru pulls his hand away telling her he's not a baby and proceeds to walk away. This makes Lum suspicious who starts wondering if she's in her original reality; she starts to ponder over what might be wrong. Meanwhile, Ataru jumps on to a trash bin and begins wrecking the branch of a Cherry blossom tree. Lum cautions him not to do so as the dimensional balance will be disrupted if he breaks it, but it's too late. Ataru breaks it and the surroundings start to get darker and Ataru gives off an bizarre grin. Lum tries to approach Ataru but she's held back by a strong gust of wind. When it stops, it seems everything is back to normal but Ataru is nowhere to be seen. Suddenly people start appearing out of emptiness, some even dressed in crazy attires, and resume their leisure activities. Lum stands in the middle of the gathering and calls out for Ataru but he does not reply.
Lum's Stormtroopers, who appear drunk although they're drinking cola, are busy enacting scenes from their favorite shows. This prompts Onsen-sensei to confront them about getting drunk. Megane steps up and tells him all they had was just coke. He announces that as it is time for flower viewing, the time to bid farewell to winter and welcome the onset of spring, they tried to celebrate using coke (as they can't consume alcohol). Sensei's words wounded their heart, and has disrespected their love for Japanese culture and if he was a real teacher he should have felt responsible. Sensei tries to withdraw quietly but the Stormtroopers decide to "dissect" him to bring back their mood and gang up on him and start stripping his clothes off.
Meanwhile, on other side of the park, Shinobu and Shuutarou are walking companionably, as the latter talks of the school's decision to take the students out for flower viewing. Shuutarou stops all of a sudden and asks Shinobu if she still cares about Ataru. She weakly replies she is not as Ataru is with Ryuunosuke and moreover, she doesn't care as he is 'good-for-nothing'. She takes a hold of Shuutarou's hand and tells him that she'd rather be with him, somewhere quieter.
Back in the main park, Ataru's trying to pick up Ryuunosuke from her yakisoba stand, so that they can go for a boat ride. Ryuunosuke asks him to go away as she doesn't speak to non-customers. This motivates Ataru to order a fried noodle with sauce but Ryuunosuke's father interferes and modifies the order into three bid fried noodles, with meat. Ataru snaps at him but, Ryuunosuke calmly asks him if he does not want the three fried noodles, leaving Ataru crushed. Although Cherry takes this opportunity to conclude that Ataru's face is "hoplessly horrible" he ends up getting beaten up the person. Cherry tries to explain that what he really meant was that his face reflects tremendous amount of unlucky features but Ataru just asks him to shut up for he is the "God of plague". However, Cherry emerges from behind Ataru, eating one of the noodles he had ordered, and warns him that disrespecting an old holy man will only draw curses to him. Ataru tries to forbid him from eating when he hears Ryuunosuke tell him that it cost 900 yen – two of the noodles were taken by Ryuunosuke's father and one by Cherry. Ataru naturally approaches Ryuunosuke and asks her if they shall leave which leads her to believe that he is going to cheat them, but Ataru has his reason for not paying – he never ate from the stall. While they are talking, Lum arrives and tells Ataru that she has been looking for him everywhere. She asks him if he has money or if he stole any and when Ataru nods his head, Lum takes out her purse and pays for the noodles and takes Ataru with her.
Ataru behaves oddly
Elsewhere, Shuutarou and Shinobu are enjoying a peaceful moment together, by the riverside. The couple almost kiss but are interrupted by Ataru, who is enraged to see his woman, Shinobu, with Shuutarou. Lum and Shinobu both speak in union about Shinobu being "his woman" and Lum takes Ataru away, leaving the rest two puzzled. They follow the pair all the way to the park, where the Stormtroopers are laying exhausted. They spot Ataru and Lum walking unitedly and are surprised to see, just like Shinobu and Shuutarou, Lum acting friendly to Ataru. Lum and Ataru arrive at a secluded part of the park but Ataru's silent which concerns Lum. Ataru responds plainly, telling her not to call him "Darling". Lum replies that she has always called him by that, and a stone falls on Ataru's head but he brushes it away. Even though a bigger stone falls on his head this time, he is still bugged and tells her not to make a fool of him. As he stops, a huge stone lands on top of his head and Ataru turns around to find the Stormtroopers, along with Shinobu and Shuutarou, spying on the pair. They wave at him to capture Ataru's attention and summons him to the group.
Megane demands to know what is going on but Ataru's confused himself to give an explanation. Shinobu wonders if there has been a change in the Onis' policy. In order to reduce the pain that people might face if Oniboshi takes over Earth, the Oni girl's groom will be chosen from the Earth. Hearing this, Shuutarou decides to overthrow the Onis and save Earth and the Stormtroopers decide to tag along with him. They charge in at Lum while Shinobu and Ataru watch this all in daze. Shinobu declares that men can not be trusted but sees that Ataru is staying back. At a distance, Lum is calling out for Ataru's help but Ataru does not seem to be bothered and decides to get going. Just then, Shinobu calls out his name and asks him if he would join her for a tea and Ataru readily accepts. Meanwhile, Shinobu and Stormtroopers are clutched on to Lum, prompting her to give them the "electric shock"; she sees Ataru and Shinobu, fading into the distance and wonders what is going on.
Lum, Shuutarou's wife
She returns home that night to find it in ruins. Inside, Ataru and his family are having a meager dinner and Ataru's father is shocked to see Lum. The others pay no attention to her and Ataru's mother tells her not to call her "mother". Lum learns the ignorance is because she won the game of tag against Ataru. In a flashback, Ataru is shown competing against Lum in the game of tag. In a quest to get married no matter what happens, he accidentally strips off Lum's bra, right in front of the crowd. Why he stood there, in a perverted state, enticed by her breasts, he did not know that Lum took away the rope from him, becoming the winner. This had some serious consequences on the Moroboshi family – the neighbors began brawling with them often, his father lost his job, and his mother's savings ran out. Lum realizes that it is a parallel reality and apologizes to them and flies away. She returns to the park and finds the portal to the next dimension about to close and so goes inside and reaches another dimension.
In the next dimension, Ataru's trying to pursue Ryuunosuke, pushing her to take a boat ride with him. She kicks him away declaring she has no time to play around with a fool like him. However, Ataru is not ready to back out and begins embracing her and rubbing on her, prompting Ryuunosuke's father to hit him with a pot. As Ataru falls, he accidentally takes off Ryuunosuke's pants, revealing her white panties and so she kicks him one more. Ryuunosuke's father inquires about the underclothing and says that as she is wearing a woman's underclothing, men will start hitting on her but before he can complete, she sends him flying, declaring she is a woman.
Lum arrives and spots Ataru lying down. She tells Ryuunosuke that it is Ataru who should be blamed as he is so fickle-minded. As a shocked Ryuunosuke watches on, Lum hugs Ataru and tells him that she has been searching for him everywhere, leaving Ataru blushing. Lum and Ataru stroll around the park and she tells him about her journey in the other dimension. Seeing this, Shuutarou arrives with his katana and announces that he is going to cut Lum into half, for cheating right in front of her husband's eyes, but Lum electrocutes him. She questions his action and asks what he is going to do to her "darling" but Shuutarou decides to commit seppuku for the same, although it is a shame for the Mendo family. Lum asks who his wife is and he replies she is. She confirms it with Ataru and he too replies she is Shuutarou's wife. Lum apologizes to them and flies away, looking for another portal. Soon, she finds one which leads her to yet another dimension.
Ryuunosuke the boy and the gentle Ataru
In the next world, the genders of the people have been reversed. Seeing how the Stormtroopers have all been turned to girls, Lum apologizes and begins to quietly leave the place, but is stopped by Megane. She tells her that her face resembles a man she knows well and declares that she loves Lum. Lum says they are both women but Megane says that's a lucky thing, as all men are dirty and she hates them. Lum is more than shocked and tries to leave again but Megane does not stop. She says that love is not about lust and delivers a speech on the topic and when Lum says she does not understand what she is saying, she even promises to teach her little by little. As they speak, Ryuunosuke arrives with fried octopus balls for the troop. Lum sees her and is happy that she got to wear the sailor fuku that she had longed to wear and comments that she looks so feminine in it. Suddenly, Ryuunosuke drops the octopus balls on to the ground and breaks down crying, and tells Lum that she is a boy. Her father also shows up and tries to comfort her, but he is in fact her mother! Lum finds the events appalling and so flees to arrive at another dimension and spots Ataru standing by the lake.
Ataru is a little different, however. He tells her that he was worried about her since she seemed to have disappeared. Lum takes a step back and asks him if he really is her darling and he replies that he is. She asks him about the game of tag and he responds by saying that he does, and that the balance of the Earth depends on the game. She asks a series of questions like who won the game, if Megane is a man or a woman, and if Ryuunosuke is a man or a woman and he answers all the questions right. She hugs him as she believes he is her "darling" and Ataru gives Lum his coat as she is cold and the two walk together. Lum starts becoming suspicious, as the Ataru with her is gentle and romantic and is not pompous about showing his love for Lum, unlike the real Ataru. She realizes that it is indeed the wrong dimension when Ataru says that he has always loved Lum, and leaves (saying "bye bye"), although disheartened. She changes world once again and sees Ataru walking through the park, holding a tree branch. Ataru spots Lum sitting on a tree, and asks her what she is doing up there. Lum flies down and asks him if he loves her and he tells her not to say something so embarrassing in the public. Lum is assured that it is the real Ataru and hugs him but to her surprise, Ataru doesn't cringe and shrug her off. She doesn't care however, as this is close enough to the real Ataru, if not the real one, and so tightens her grip on Ataru leading him to yell and try to shake her off, like always.
- "Resistance is Futile, Jinguji. The Moo Empire will inevitably triumph" - Megane
- "You brought us down. To get back in the mood, we'll dissect you." - Megane
- "The Earth wasn't beaten.... Just you! Now we're spat upon by our neighbors, father lost his job, and my secret savings ran out...!!" - Ataru's Mother
- "I see...there's nothing I can do. This will shame the Mendou family for generations. Thus, I have no choice but to commit seppuku at once!" - Mendou Shuutarou
- "How awful! I screwed up again." - Lum
- This episode was one of the top rated episodes of the Urusei Yatsura series.
- After the Stormtroopers begin stripping away Onsen-sensei's clothes, Kotatsu-neko and the Tomobiki High School Principal are shown having tea beside a kotatsu.
- This episode makes many references to various science fiction series like Star Trek, Star Wars, Godzilla, and Ultraman. First, the Stormtroopers are shown imitating various Star Trek characters (the Borg), and later a few children are shown wearing masks similar to those of Ultraman's.
- The last scene where Lum and the real Ataru, holding the broken cherry tree branch, reunite has been reanimated and used in the fifth animated movie of the series, The Final Chapter.