Author's Note: So this is vaguely AU-ish because it's ignoring the events of Operation I.N.T.E.R.V.I.E.W which heavily implies that they all stay KND operatives. Also it runs with my headcanon that Numbuh 4 is the youngest of Sector V which is probably not true but I can add that to the AU status :P I tried to do a thing where their 'Numbuh's and their actual names were only used at specific times (which I hope you'll realise what I mean when you read it) so please excuse the awkward over use of their Numbuhs. This is really rough and I just wrote it because the idea was stuck in my head so it's not supposed to be overly good, anyway I hope you enjoy :)
Numbuh 3 and Numbuh 4 were my KND OTP :3

Numbuh 4 stared at the ground, twirling his foot. His cheeks were bright red and he was desperately trying not to look Numbuh 3 in the face, he always lost his nerve when he did that. But it was now or never, who knew if he'd be able to admit after that day.

Numbuh 3 smiled widely at him, silently urging him to spit out the words she'd been waiting, like, 20 bajillion years for. This was it.

"You know, Numbuh 3, I've been wanting to say this for a… a long time. And this may be the last chance I get to say it but…" he trailed off and she knew that he was going to change the subject like he always did part way through. But she tried not to let her smile slip because then he'd feel bad. Numbuh 3 was about to change the subject herself to get the disappointment over with when suddenly Numbuh 4 kissed her on the cheek.

She gently touched the spot that he had kissed and stared into his beet-red face, her own beginning to match the colour.

"I'm… I'm sorry I didn't say any-anything before but I was worried that you might not-" Numbuh 4 began but he was cut off as Numbuh 3 tackle-hugged him to the floor.

"You finally said it! Oh, Numbuh 4 I've been waiting so long!" she smiled into his shoulder and his surprise turned tender as he slowly returned the hug.

"You knew all along? And you never said nothing?" he asked.

"Mm-hm" she mumbled. They sat up from the hug and looked at each other, Numbuh 4 confused but happy and Numbuh 3 beaming. Numbuh 4 began to go red again and looked away slightly as he mumbled.
"Do you… maybe… want to…?" Numbuh 3 caught his eye and a tender look passed between them, they leant in closer and closer until…

Of course, it was at this moment that the KND operative walked in. Immediately the ginger boy shied away, covering his eyes with his arm.

"Ew, cooties!" he gagged, while Numbuhs 3 and 4 quickly moved a safe distance away, although for the first time Numbuh 4 kept his hand holding 3's, not caring that anyone was watching.
The ginger kid, Numbuh 173, pulled his arm away when he saw the cooties had stopped and suddenly the atmosphere became serious.

"I'm, I'm sorry Numbuh 3 but… it's time." he stood there smiling sadly as Numbuhs 3 and 4 had their final conversation.

4 scratched his ear, looking away from 3's face so she wouldn't see his frown.

"So… I guess this is it then, huh? The big 1 3." Numbuh 3's smile faded.

"Yeah… I'm sorry I'm leaving you all alone Numbuh 4, but your birthday isn't 'til next month... I got you a birthday present!" her smile came back, as big and goofy as ever "It's in your room in the tree house but you can't look at it until your birthday! Promise me Numbuh 4!" Numbuh 4 couldn't help but be infected by Numbuh 3's smile and he nodded, but some cruddy things were in his eyes so they were a bit wet as he promised Numbuh 3 he'd wait. "Pinky swear?" Numbuh 3 held out her sweater covered little finger. He'd miss Numbuh 3, her bubbly laughter and her annoying cute singing and even her stupid, cruddy, green sweater and oh, who was he kidding? He was crying as he pinky swore with Numbuh 3, but it was definitely very manly crying and it didn't make him a baby at all.

Numbuh 3 smiled her biggest smile and walked off towards Numbuh 173, looking back once at 4 just before they walked through the curtain that took her to the decommissioning chamber.

"Crud! The Birthday Present!" Numbuh 4 shouted at himself as he remembered the birthday present he'd bought for Numbuh 3. He ran around the waiting room searching for where he'd hidden the thing before Numbuh 3 arrived. He was gonna surprise her and everything, stupid, stupid, stupid!

Finally, hidden behind a plastic chair he saw the orange ear of the Forget-Me-Not Rainbow Monkey he was supposed to have given Numbuh 3 before she went, but maybe he still had some time?

The unmistakeable sound of the decommission-er zapped through Numbuh 4's ears and he sat down heavily on the floor. Through the curtain walked the girl he had liked liked, but she was different. There was a gold loop earring in her right ear and she wore a green headband. She still wore her green sweater, but it didn't cover her hands anymore and she wore various green bracelets, she also had a lighter green short skirt over her leggings. Numbuh 4 gazed forlornly at his gift, but then figured that he might as well give it to her.

"Hey Num- Kuki, I um… got you this for you for your birthday." He held out the Rainbow Monkey and smiled hopefully, she had to still be the same person, right? Kuki looked at the Rainbow Monkey disdainfully and then took one look at Numbuh 4 before brushing past him.

"Sorry kid, go play with your silly toy on your own. I have to, like, do my nails and stuff." Numbuh 4 stared at the Rainbow Monkey as the door slammed shut. He stared at it as he took the bus home and he stared at it as he sat on the floor in his room. He stared at it and stared at it and curled his hand into a fist and threw the cruddy thing against the wall but it didn't break so he jumped on it and ripped it apart piece by piece by piece screaming into his hoodie so his Mum wouldn't hear. He was so STUPID. She'd known, she'd known the whole time and felt the same way and he waited until the last possible second to even admit that he liked her! And now she was gone. She was the enemy. A teenager. A cruddy, cute, stinking, pretty, stupid, funny teenager! And he was just a stupid kid. He'd been so close but now they were worlds apart.

(~~*~~)

He almost hadn't gone to get Kuk– no – Numbuh 3's present, he thought it would be too painful, but on his thirteenth birthday he picked it up before heading to the decommissioning chamber. This time he sat in the waiting room on his own while they messed with the dials or whatever cruddy sciency stuff they needed to do. Numbuh 2 would have known, but he'd been decommissioned a few months back. Numbuh 4 was the only one of the old team left and his new team were nice enough, and were great at kicking adult butt, but they waited out in the stands. He shouldn't have been in the back with Numbuh 3 on her birthday but she'd asked him to be there and he could never say no to her, not when it really mattered at least. He toyed with the Rainbow Monkey wrapping paper, reading for the fiftieth time Numbuh 3's unmistakable loopy handwriting telling him not to dare open it before his birthday. Should he open it then, or wait until he'd been decommissioned?

Someone walked through the curtain and Numbuh 4 knew it was time. He turned around ready to leave his memories behind but there wasn't a KND operative standing there, there was a teenager. The girl who had been Numbuh 5 stood in front of Numbuh 4, but she couldn't be there, she'd been decommissioned a long time ago and teenagers weren't allowed in the decommissioning chamber unless it was their 13th birthday.

"N-Numbuh 5? How are you…? What are…?" Numbuh 4 stammered. Numbuh 5 smiled like she used to, she kind of looked like Cree now but she still had her hat.

"There's something you need to know about decommissioning, Numbuh 4, it doesn't happen to everyone. Sometimes there are operatives that the Kids Next Door want to keep as teenagers and even beyond that. Sector V is full of those people." Immediately Numbuh 4 blurted out,

"Even Numbuh 3!?" but Abby pulled her hat down over her eyes, her smile gone.

"I'm sorry Numbuh 4, but Kuki… Something went wrong, they sent the order to decommission because of some error in the 2x4 technology. Numbuh 5 couldn't stop it in time… She's really been decommissioned." Numbuh 4 threw the present to the ground.

"Of all the stupid, cruddy things!" he shouted while beating the air uselessly with his fists. Abby looked on sadly.

"There is one way of being with her again…" she trailed off, uncertain. Numbuh 4 immediately looked up and stepped closer.

"What, how? I'll do anything!" he pleaded, but Numbuh 5 looked away with her hand to her chin. She looked at Numbuh 4's pleading eyes and sighed.

"If you go through with the decommissioning, if you become a teenager properly, then there won't be anything in between you and Kuki. But if you stay with the Kids Next Door, then there will always be the barrier of you remembering your past and her… not. The trouble is you'll still see her as Numbuh 3 while she'll know you as Wally, the weird Australian kid who thinks he knows her. It's up to you Numbuh 4."

"But… How do you know that Kuki and I will be… friends… after my memory's all gunked up?" Numbuh 4 asked, but Numbuh 5 just shrugged her shoulders with a helpless expression.

It was a huge decision. Numbuh 4 was being given what he'd always wanted, he could stay in the Kids Next Door, fighting the adults and saving kids for the rest of his life. But then he'd probably lose Kuki and… and he wasn't sure if he could do that. What was more important to him? He looked at the present on the floor, he looked at Abby, he looked at the present again.

He picked it up.

(~~*~~)

Wally sat down at his desk for form room, it was a pretty relaxed atmosphere because the teacher was late, which was a rare occurrence. He finally had time to look around the class without the threat of detention looming over him. The cute Asian chick was sitting at the back of the class, it was pretty rare to see her without her gaggle of friends. Maybe it was finally his chance to talk to her. He got up and attempted to swagger over but ended up tripping over a seat. With his face on the floor he heard a giggle and sat up blushing. The girl smiled while laughing into her hands which were covered with her green sweater for a second, but then she moved them back to help Wally up.

"That was funny, do it again!" she teased, pushing his shoulder and Wally smiled awkwardly, combing the back of his hair with his hand from nerves.

"I'm Wally. I… um… like your sweater." he finally said with an awkward grin. The girl beamed, her eyes shining like a child's.
"Thanks! I'm Kuki and I like your hoodie." Wally looked down at his orange and white striped hoodie and smiled with fond memories.

"Thanks, a friend got it for me for my birthday."