Yes I know, this story isn't one of the ideas I shared when I finished my last book, but this idea just came to me. It's inspired by many one-shots and cute little comics I've seen. So I wanted to share my take on this storyline.

It had been five years since the two now adults had been given their Miraculous'. Marinette was self-employed and ran her own online store. Adrien while he no longer worked for his father still modelled but he had taken to photography and his favourite photographer had agreed to give him lessons as long as it didn't affect his other jobs. On top of their jobs, they trained together often with Master Fu. Not that they knew they were training together mind you, the two had managed to keep their secrets and both had their own lives.

Today they were working with a new set of powerups that Master Fu had found in the book. However, the page was torn so Master Fu wasn't positive he had gotten it right. As per usual the two competed to try it first. "My Lady, you went first last time, do we really have to complete again?"

"Rules are rules Chaton, and if I remember right you wanted to make it a challenge." Ladybug winked getting ready to play the silly game.

"I was 18! We were 20 now is this really necessary?" Chat winner.

"Yep!" Ladybug popped the 'p'.

He lost again, which was normal. She could read him too well, that and she was lady luck so he really should have thought this through as a teen.

Today's power-up was supposed to increase their skills, Hawkmoth had people that worked for him now, so the battles had gotten harder so this power-up was desperately needed.

Ladybug quickly popped the power-up flavoured cookie in her mouth. Master Fu had found a way to have holders eat the power-ups rather than the Kawimis, making it easier to power up in battle.

For a moment nothing happened, she was about to speak when a pink light engulfed her. When the light fades, Cat looked a lot taller than normal and Master Fu also seemed tall. "What happ..." she stopped, her voice, why was it so high? She'd covered her mouth with her hands, then she saw her hands, they were small.

"Lady... Ladybug? You're... you're so small?!"

"MAster! What happened?" Her voice was whinier than normal.

"I think... I think, I made a mistake and made you a child." Master Fu sighed.

"What do we do?" Chat hoped there was an easy answer.

"I'm not sure, but Ladybug as much as I have discouraged this in the past, I think I need you to detrasform." Master Fu sighed, he knew the risk he was putting the two in. The two heroes where best friends outside of the masks, but the didn't know that. Would the two handle it well? He knew Marinette had less of a crush on Adrien but her heart still belonged to him, and Chat's still to Ladybug.

The now little Ladybug titled her head, "Detrasnform?"

"Yes to your civilian self, we will see if the effects wear off."

"What do you mean? I'm Ladybug?" Her eyes filled with tears, clearly confused and overwhelmed.

"Woah Woah, little bug, it's okay!" Chat picked up the now little girl who was on the verge of tears. "Take a deal breath." She did. "You and I aren't superheroes all the time."

"We aren't?"

"No, we have lives outside of these masks. Don't you remember?" The little girl shook her head. "No? Well, maybe detransforing will help you remember. Go with Master Fu and do what he says okay? I'll stay here just in case your memory comes back, you wouldn't be happy if I found out your identity."

"O...Okay." The tears rolled down her cheeks.

Master Fu and Ladybug walked away together. "Alright Ladybug, say spots off."

"Spots off." The little girl said. "Tiki!" Mari clapped her hands and pulled the kawmi towards her cheeks. The Kawmi dried the girl's cheeks.

"Marinette! Master, what happened?" The small creature looked at her holder.

"A power-up mishap. It made her a child."

"Marinette! That's my name! But I can't remember where I live, or what I do, or where my parents live or anything!" She started to cry again.

"Master what can we do?" Tiki asked. "No one can know she Ladybug and her friends and parents can't know she's a child. It would cause a mess."

Master Fu sighed, "I can't have her stay here, to many people come here for me to suddenly have a 'grandaughter' however, she could stay with Adrien... After all, he's the only one who can know...." Fu tapped his chin.

"Adrien?" The little girl tilted her head. "Who is that?"

"You'll see. But first, let me talk to Chat Noir." Master Fu joined Adrien in the other room. "She can't remember anything about her normal life. It's going to take some time for me to figure out. So she needs to stay with you. In your civilian form."

"How!? Sure I'm not front cover magazine type anymore, but I still make the tabloids every once and a while. Having a kid around me will not go unnoticed. My father will kill me." Adrien started to panic.

"You're still taking Chinese Lessons aren't you?" Master Fu winked. "You're simply helping out your Chinese teacher with his granddaughter who came to visit and he can't keep up with her."

"Well, I suppose that would work. The three of us will need to be seen in public together. And What about battles she can't fight like that." Chat didn't want his lady to get hurt.

"Well once you see her, you'll be able to guess who your teammates have been in the past few years, you can give two of them their Miraculous' full time and tell them what's happened to Ladybug. They will help you fight and LadyBug can still clean up after the fight and maybe even give a lucky charm, we will have to test it. We've used invisibly before, maybe we can use it now, so Hawkmoth doesn't know." Fu smiled.

"And this is why you are still the garden." Chat smiled, "Well can I meet my little lady?"

Master Fu went to the other room and brought Marinette out. "Hi, Kitty!" She waved.

"Marinette?!"