Naruto was, to put it lightly, annoying to Sasuke. He never could seem to keep his mouth shut, constantly blabbing about this or that; he just always, and the means always, had to be the center of everyone's focus, constantly pulling stupid pranks and little jokes to get the focus back on him; and not to forget just how childish he was in general! You'd think that someone would've taken responsibility and taught him some basic manners at the least, but no! He couldn't even eat like a decent human being, not even at his current age of twenty!
Sasuke was currently leading said annoying blonde to his house. The blonde had fallen for the 'I'm only bringing you here to shut you up' ruse, when in reality Sasuke was going to fix the other's immaturity. They had both just finished training, and everything was going perfectly. He offered Naruto some tea that he'd laced with some diuretics before suggesting they shower. He knew that they'd take a good thirty minutes before kicking in, the allowed Naruto to shower first, even giving him clean clothes to change into afterwards.
About twenty-five minutes later and Naruto exited the bathroom, fully clad in some of Sasuke's clothes from his gennin days. It was almost saddening to see how much Sasuke himself had grown, while Naruto's genetics did him no such favor, leaving him at roughly 5'2", so even some of Sasuke's older clothing hung limply from his skin-and-bone frame. Sasuke frowned when the saw that. His stupid jumpsuit hid it well, but now his malnourishment was clear to be seen. Sasuke gestured for him to wait on the couch while he cleaned off, leaving the blonde with a warning not to break anything or go exploring anywhere without him.
He was about fifteen minutes through his shower when he heard a knock on the door. He let out a "Hn." to acknowledge that he heard, and waited for what the knew was coming. "H-hey Sasuke, I know that you said not to go exploring anywhere, but I really need to go. C-can I please use the bathroom?" Sasuke smirked victoriously, feeling his answer roll off his tongue. "The door's locked, dobe. Just wait five minutes." He knew Naruto wouldn't last that long. Naruto sounded so much more desperate than he thought he would. The five minutes ticked by, and soon Sasuke was dried off and opened the door to a sight that he honestly wasn't expecting to see. There sat Naruto, on his knees, desperately clutching himself, refusing to wet himself.
Sasuke had expected him to already be drenched and begging for forgiveness, but it seemed that he underestimated the dobe's determination. He was preparing to scratch this plan and try a different time, when Naruto shuddered as the steamy air from the bathroom hit him, forcing his control to waver, but that one split second was enough. Soon there was an enormous golden puddle surrounding a now sobbing and hysterical blonde. Sasuke almost felt bad for forcing this on the blonde, but it was all going to be for the better. He sighed, pinching the bridge of his nose as he looked down at the boy, for this was no man, in front of him. "Get up." Naruto, still sobbing, shakily rose to his feet. "Now, you're going to clean yourself off again while I deal with this. If I'm not back in here when you're done you are to stay sitting on the toilet."
Sasuke quickly cleaned up the mess, and left to go buy diapers. He couldn't have had them before without looking suspicious, and now he was grateful that he had waited, otherwise he would've grabbed the wrong size, thinking Naruto was at least two or three sizes larger than he apparently was. As he was leaving the diaper isle in search of the proper changing equipment he came across a small fox push that he just knew that Naruto would love. It was his favorite animal, and color, and was just the perfect texture and shape to cuddle with. Without much thought Sasuke grabbed the plush from the shelf and continued his browsing of the infantile items.
As he was purchasing the items a pacifier with an adjustable strap caught his attention. He stepped over to grab it, quickly adding it to his bag before he left for his house, hoping that Naruto had actually listened to him. He knew that after Naruto had held it for so long that his bladder would be weaker than normal, and he really didn't feel like cleaning up another puddle.
Sasuke arrived home uninterrupted and already worried about the interactions to come. He knew that the blonde would not take kindly to being forced back into diapers, but it was a necessary step in correcting whatever Naruto had been taught in his early childhood. He made his way to the bathroom and was met with a still sniffling blonde that was seated on the toilet. Now came the hard part.
Sasuke cleared his throat, alerting Naruto of his presence, and almost immediately the waterworks started back up. Tears were quickly pooling in the corners of his eyes, and he had started stuttering out apologies. Sasuke only held up a hand to silence the boy and laid out the changing mat that he'd purchased. He pointed to it and looked pointedly at Naruto. "Lay down." It was not a request, and Naruto knew it. He bit back any of his questions and carefully lowered himself onto the mat, being sure to try and cover himself. He squeaked when Sasuke moved his hands away, and uncovered his manhood. He was squirming about, uncomfortable with being so exposed. "Stop moving." Naruto let out a pitiful whine as he was forced to lay still. Sasuke pulled out some baby oil and baby powder from the bag, and carefully applied both to the whining blonde. Sasuke was getting fed up with the nonverbal complaints from the blonde. "You either shut up and take your punishment properly, or I make you." Naruto's eyes widened in fear, and he hurriedly shut his mouth with an audible clack. Sasuke huffed and pulled out the pack of diapers, quickly getting one onto the the terrified blonde that lay before him.
Sasuke pulled the blonde into a sitting position, waiting for his reaction. Surprisingly the only reaction from Naruto was the blush that raged across his face from being fully exposed and diapered. "S-Sasuke, why an I i-in a diaper?" Sasuke smirked down at the blonde while raising an eyebrow. "Do I really need to answer that?" Naruto looked down, clearly ashamed of himself. "It w-won't happen again. S-sorry Sasuke." He knelt down to the blonde's eye level. "It's okay, Naru. Baby boys have trouble getting to the potty. That's why they wear their diapers."
While Sasuke could've used his Sharingan to brainwash the boy, it would be far more effective in the long run for Naruto to accept his new position as a baby without any outside influences. Naruto was not having that answer, however. He was confused, and his stomach hadn't been feeling good the past few days, which only added to his current misery. "I'm not a baby! I'm an adult! Sasuke, you can't do this to me! Let me go home!" Tears of frustration and fear were still present in Naruto's eyes. Sasuke shot a hard look at the boy, causing him to shrink in on himself. "You call yourself an adult, but you act far from it. You've always been far too childish, and just a few minutes ago you couldn't even keep your pants dry. You're no adult, Naruto. Not in my eyes, nor in anyone else's."
By now Naruto was sobbing again, desperately trying to deny those statements. Sasuke sighed and rubbed his temples, Naruto's crying was starting to give him a headache. "Naruto! Be quiet! Crying won't change anything. I've already spoken to Hokage-sama about this, and she agreed. This is going to be better for you and for everyone else." His crying stopped for a total of about five seconds before it was back full force. "Liar! Baa-chan would never let you do this to me!". Sasuke sighed, this is about the reaction the expected from the loudmouth blonde. He dug through the bag in search of the pacifier that he'd purchased earlier.
Naruto's hiccup filled cries were silenced by the silicon nub that'd been placed in his mouth. He tried to spit it out, not being a fan of the foreign object that was muffling his cries, but it was too late, as Sasuke had already secured the strap in the back of his head. Sasuke sighed again, already ready to go to bed for the night. He fixed his sharp gaze back on Naruto, who flinched harshly at the near glare that was fixated on him. "You, Naruto Uzumaki, are going to stay quiet and listen to me while I explain the full situation and what will be happening because of it." He got a small, tearful nod from Naruto, and proceeded with his explanation of what happened.
"As I'm sure you're aware Jiraiya, Tsunade, and Orochimaru were able to eliminate the Akatsuki after Orochimaru's mind had been cleansed of the manipulative genjutsu that he'd been under the influence of for years, and that Sarutobi-san passed on his title of hokage down to Tsunade. What you didn't know is that all of us, meaning the three sannin and all of the rest of the rookie twelve were told about your past." Naruto froze in place at that statement, shaking lightly. "We know about what you went through, so that's why Hokage-sama decided to go through with a rather unconventional method of therapy, are regression. Not only should you get the childhood that you deserved, you will be raised with the proper parental guidance and hopefully you will learn some proper manners from this, although that may be asking for a bit much. Regardless though, this is what's been suggested by a medical standpoint, and you are going to at least give it a shot."
Naruto was still in shock about them knowing about his past. He tried, he tried so hard to leave it behind him, but it was all rushing back. The starving, being poisoned, beatings, but most painful was the isolation. That was the one thing that couldn't properly be fixed even after years of having friends, he was haunted in his nightmares. Tears were falling and he couldn't breathe. Not until he was hugged.