I don't own Urusei Yatsura, but you already know that. If there are plot holes, and there most likely are, don't bother pointing them out. There will definitely be some OOCness. For this fic both are a very hard thing to avoid, so try not to worry about it and just enjoy.

On a dark night in one particularly eventful district of Toukyou, Japan, some suspicious activity was going on by the town water treatment facility. At first glance it looked like a young girl in her mid-teens was riding a horse towards the building, followed by something that couldn't clearly be seen in the dark. When she got into the light provided by a nearby streetlight, one could see that the horse the girl was riding was fake with two people working as the legs while a third person followed clanking coconut shells to provide trotting sounds. Judging from the outfits, the three men were kurokos working for the girl.

The sound effect kuroko stopped what he was doing and walked up to the closed gate to the water plant premises. After pulling out some sort of skeleton key, he unlocked the gate and opened it so the girl could ride right into the restricted area, but got back into his previous rear position first to begin making hoof-step sounds again.

"Freeze!" A man's voice suddenly shouted as several bright lights flashed from the right side of the girl and her crew. Blinded and surprised, they inadvertently obeyed the command. When they regained their vision, they saw several police officers pointing guns at them from behind a police car that had been hidden from view until now. "Step down and put your hands above you head."

The girl gave an annoyed look, as if experiencing nothing but a minor inconvenience. "Do you know who I am?"

"You're a trespasser and we have reason to believe you have illegal and harmful intent. Now get down and place your hands above your head." One cop replied.

The girl did nothing, as if the order was simply an option. And her expression was smug, like she felt they couldn't do anything to do to her. Like they were all bark and no bite, even if she continued what she originally came here to do. Feeling untouchable, like she often did, she turned away and motioned for her kuroko to continue on their task. Like drones, they obeyed without a thought. Until the sound of a few shots were heard, and the four of them fell unconscious.

"Don't you think that might have been uncalled for?" One man asked the one who fired the tranquilizers.

"She obviously wasn't going to come willingly with us, and it looked like she was going to pretend we weren't here. Our orders were to stop her." They retaliated.

"Do you think she's the culprit?" A third officer asked.

"She's the only one who's come here after hours all week, and she used illegal means to enter. She's definitely worth taking into custody." The first cop answered.

"Should we call her parents? She is a minor after all." A fourth officer asked them.

"No. If she's doing what we think she's doing, then it's best not to get anyone else involved for now. So let's take her back." The second cop told them. They quickly gathered up the unconscious bodies of the young girl and the three kurokos and took them to a police station two districts away. They had a hard time bringing the fake horse body with them, but since it was evidence they couldn't simply leave it behind.

In police headquarters two districts away, the girl and kurokos were contained in separate rooms, sitting at tables awaiting someone to interrogate them, all while being watched behind two-way mirrors.

"So what do we know about her?" A high-ranking officer named Kawakotsu asked a man named Akitsuna, while keeping an eye on the girl.

Akitsuna presented a file filled with identifications. "The girl has been identified as one Mendou Ryouko, youngest child of the Mendou family. Do you know of them?"

Kawakotsu nodded without tearing his gaze from the teenager. "Yeah. One of the wealthiest land and business owners in the country with strong connections. Hard to believe one of them would be involved in something like this."

Akitsuna looked through the folder again. "It appears that Mendou-san attends an all-girls school with good grades in chemistry. With her family's resources it was easy for her to get everything she needed for the substance used."

"That answers that question. But still, why would she do this for so long?"

This time Akitsuna didn't look down. "Judging from past actions and previous personal references, she's a classic example of the spoiled rich girl. She seems to delight in toying with people and has even been seen carrying explosives around. And it appears she's never been told 'no' or disciplined for misbehaving. Maybe not even so much as a slap on the wrist. So naturally she grew up believing everyone is here simply to entertain and cater to her."

At this time someone else came up to the two men. It was a woman with short black hair and green eyes, wearing dark clothes.

"Hello Detective Kurama-san." Kawakotsu greeted her.

She bowed her head back before speaking. "We've analyzed the chemical she was carrying on her person. It's a rather unusual compound, but the main components appear to be hallucinogenics, pain-relievers, and ecstasy, with a slight hint of steroids."

"So what does it do?" Akitsuna asked.

Kurama appeared to struggle to find the best way to answer. "According to our drug experts, in theory this compound when ingested causes unrealistic, almost impossibly absurd, delusions about reality. The victim begins to forget what's real and unreal, and is likely to believe fantasy is reality. And other users become open to suggestion, so they actually could be convinced effortlessly that what the first victim believes is real for them too. And as long as they keep taking it in regularly, they keep believing these illusions, completely numb to everything around them. It's habit-forming behavior too so people tend to repeat their actions in various situations."

"The chemists theorize that this drug may have one of three effects on a person's mind." Kurama continued. "One, it might convince someone that they are someone else completely with some sort of faulty fake memory they never question. For example, a cosplayer would become convinced they are the character they dress as. Two, it might convince someone they are what others claim them to be. For example, a 'dumb blonde' would be convinced they really have no brain and are supposed to be their stereotype. And finally, it might not effect a person's mind or personality at all, just how they see events around them. Basically such a person wouldn't change, but would see everything else the way others do like it was reality."

Kawakotsu looked uneased and bothered. "So this girl has a potential mind-altering drug that she was planning to put into the town's water supply, thus affecting everyone in town? Are you sure about it's effects?"

Kurama nodded. "Definitely. She's been doing this for a while, if you look at how long the people in the district have been acting oddly. I went there a while ago to investigate, and ended up falling victim myself. Somehow, I had become convinced I was some kind of alien similar to karasutengu's and was in a Sleeping Beauty-like situation. I left, thinking I had returned to my 'home planet,' but actually went a few districts away from the drugged water so the effect wore off. Since then I've been trying to figure out just what the hell is going on in that town."

Akitsuna looked at Ryouko then back to Kurama. "How long did it take to wear off for you?"

Kurama looked upwards, a sign that she was trying to recall a memory. "At about the eighth day away from the town, I still believed I was an alien, but I at least saw and felt the real world around me. The next day it became much easier for me to remember who I really was, and by the end of that day, I felt cured of the madness. So eight to nine days is a good estimate."

Kawakotsu nodded. "Okay. First send out a notice to the whole district, and the surrounding ones in case they're contaminated too, to not drink or use any tap water of any kind. If asked, say there's possible infection risk or mercury poisoning, or something like that. Then double check all the water in the treatment plant to ensure there's no build-up of this substance or residue left before giving the okay to the populace to use it again. Then we just wait a little over a week and hope everything returns to normal there."

Akitsuna and Kurama nodded. "What about the girl?"

"Keep her in custody for now. But don't inform her kin until the effects of the chemical wear off. If we notify them now they most likely won't see reason."

With that the police put their plan into action. The potentially contaminated water supply was closed off from the public the next day, for health reasons the people were told, and checked to ensure it was drug-free. For the next week, the residents drank water free from mind-altering drugs. And on the eighth day after they cut off the supply, which was a Monday, the police were anxious to see the results.

On said Monday, one 18 year-old boy named Moroboshi Ataru woke up at the same time his 'roommate' Lum did. Her younger cousin Ten still slept peacefully, curled up and looking very innocent. "Uhhh... good morning, Lum." He greeted her, still feeling groggy from sleep and rubbing his eyes.

Lum did and felt the same, but smiled. "Good morning Darling. Sleep well?"

He nodded. "Yeah. Did you?"

Lum stretched before answering, and Ataru couldn't resist admiring her figure as she did so. "I guess. But I'd sleep better if I knew I'd wake up next to you."

More awake now, Ataru glanced at the closet before looking back at Lum. "Say, Lum, how can you tolerate sleeping in a closet? Doesn't it get awful cramped in there?"

Lum sat down and yawned. "Yeah, it does. But it's worth it to see you every morning."

"You deserve better. Why don't you move your futon out here tonight?" Ataru suggested, surprising them both. 'Whoa, where'd that come from? I never thought like that before. But, it's not that bad an idea. I mean, as long as we don't share the futon... yet, it shouldn't be a problem.'

Lum blinked in surprise. "Are you... sure, Darling?" While she sounded happy, there was a hint of hesitation in her voice for some reason.

"If we... keep some space between our beds it shouldn't be too bad." Ataru told her bashfully, scratching the back of his head. "I... kinda feel like a jerk for making you sleep there in the first place. As long as you don't... rush things, it should be OK."

Lum grinned brightly. "Thank you, Darling." Her smile quickly vanished when Ataru suddenly looked at her with sheer shock written all over his face. "Darling, what's wrong?"

"L... Lum, I... just noticed something." Ataru struggled to say. "Your... your horns are gone! And your hair is black!"

Lum gasped and felt her scalp. She couldn't feel any horns on her head, and she pulled some hair into her sight and confirmed it was indeed black. "Wha... what the hell happened to me?"

"I don't know, but you almost look... human."

Lum got scared. She didn't bother to see if she could fly or generate electricity, since without her horns she couldn't do those things anyway. 'Wait. Why does the idea that horns are necessary for those things to be possible sound so weird now? It's a natural fact of oni biology.' She suddenly wanted to cry, so she threw herself at Ataru and did just that. And surprisingly he wrapped his arms around her without a second thought to comfort her.

"Lum, maybe you should stay home from school today." Ataru suggested.

"Don't we have an important test today that we shouldn't miss?"

"Are you up to it?"

"As long as Ran-chan doesn't try anything funny." Lum answered.

With that, the two got dressed in their school uniforms, separately of course, and got ready to go to school. After saying goodbye to Ataru's parents, both walked along the route they usually took, and Lum felt awkward about not being able to fly. As she thought about it, a really scary thought entered her mind.

'I... I can't remember how to fly anymore. How could I have forgotten that? I mean, I just jump into the air and... and... then what? What do I do to keep in the air or move around? Without wings? Why, for the life of me, can't I remember?'

Ataru saw her look at the ground in confusion as she walked alongside him. Unsure how to comfort her, he just kept looking ahead, and saw a rather attractive girl walking by. He was tempted to go ask her out, and his feet started to move in that direction, but almost impulsively, he stopped and kept close to Lum.

'Why'd I do that? Why didn't I go and ask for her name, number, and address? Then again, that would kinda make me look like some kind of sick stalker. What the hell made me think any girl would go for such an approach anyway?'

One thing that really surprised Ataru was when a few moments later, he saw a group of girls on a morning jog in flattering outfits, and thought nothing of it. Sure, there were some perverted thoughts, but nothing like the kind anyone would expect from the infamous lecher. Normally, scenes from an X-rated film or M-rated fanfic would appear in his mind at times like this, but all that came to him now were ones more PG-14. It was as if his overactive libido had nearly died out.

When they got to school, most students immediately noticed Lum's new unintentional look. Embarrassed, she kept her head low and held Ataru's hand for comfort, who surprisingly didn't object. They got to their classroom without being bothered, but once their classmates saw Lum, she was the complete center of attention. Before everyone could finish their questioning, Lum raised up both hands to silence the group of students.

"I don't know how it happened. I woke up like this and I'm even more surprised and disturbed by this then you are. Let's just not make a big deal about it, okay?"

With that, the subject was dropped and the teacher came in. Classes went on as normal and they had their big test today that would count towards their graduating grades. Lunch came and Lum and Ataru took a seat under a large cherry tree to eat. Lum was glad that Ataru wasn't trying to keep his distance from her like he usually did. She didn't even have to ask him.

For the rest of the day they noticed several other things that were greatly different than normal. Lum found her bra no longer held several small alien devices and she could no longer contact her UFO. Mendou's sword was confiscated by a teacher saying it was illegal to bring dangerous weapons onto school grounds, making everyone wonder why this never was a problem before. When Shinobu tried to do some heavy lifting, her great strength seemed to disappear like Lum's oniness had. Ryuunosuke was surprised when her father referred to her as a girl, but figured it might have been a slip of the tongue. Kotatsuneko was in the principal's office as usual, but was normal cat size. Sakura actually got full while eating her lunch. Cherry showed up, but he seemed to be exactly the same as always, much to everyone's displeasure. By the end of the day, everyone was looking for signs of the approaching apocalypse, except Onsen Mark who took solace in a bottle of sake. At least not everything had changed.

When Ataru and Lum got home, his parents greeted them and told them both they were worried about Ten. He apparently lost his own horn and his hair had turned black too. But what was oddest was that he started acting and talking like a 2-3 year-old boy instead of the Jariten they all knew. So far nothing else seemed to change around or in the Moroboshi house.

Night came and Ataru and Lum were getting ready for bed. When Ataru got his futon unrolled, Lum sat next to him. "Umm... Darling? I'm still really unsettled by everything today. Could I... just this once, bring my futon out here? It might help me relax to know you'll be the last thing I see tonight and the first thing tomorrow."

Ataru nodded. "Sure. Don't you remember I suggested that earlier today?" Lum blinked, then scoffed at herself for forgetting. With that settled, the two teens got ready for bed, with Lum keeping her cousin Ten close by so he wouldn't get finicky. Both wondered just what tomorrow would bring, and if it would be better than today.