The first day of Kindergarten. It was supposed to be a happy, exciting day for five year olds everywhere. Little boys and girls would be leaving their mothers and fathers for perhaps the first time. It was a brand new adventure for them, an exploration into something unknown and awesome. At least. That's how it felt for Eren Jaeger.

"Mom, come on, we're gonna be late!" The little boy yelled happily, waving his mother and adopted sister on.

Mrs. Jaeger merely smiled. "We're right behind you, dear. Aren't we, right Mikasa?"

The black haired girl nodded as she held onto her adoptive mother's hand, her face hidden behind a bright red scarf. Eren looked at her and then grinned toothily.

"Mikasa, whatcha waitin' for? Wanna race?"

Before Mikasa could give her answer, Eren had already taken off, excited to see his new school. Mrs. Jaeger sighed, giving a tired smile. "Mikasa, can you promise me something?"

Mikasa looked up curiously.

"Protect him, please. His father and I won't always be there to watch over him now, but you and he are in the same class. You know how wild he can get sometimes, and I don't want him getting hurt because of it. You'll take care of Eren, won't you, Mikasa?"

"Of course," the black haired girl mumbled. "I'll always protect Eren."

Once they reached the part of the sidewalk just outside of the kindergarten playground's entrance, Mrs. Jaeger bent down and hugged Mikasa.

"Have a good day, darling. I showed you where to get off the bus at, I'll be waiting there for you and Eren at the end of the day."

Eren stood waiting for them just inside the gate, tapping his foot impatiently.

"Hurry up, I wanna go play with the other kids!"

Mrs. Jaeger let go of Mikasa with a final kiss to the top of her head before sweeping Eren up into her arms and placing feather light kisses all over him.

"And look at my little man, all excited for school!"

"Mom! I'm too big for that stuff now! I'm in kingarden now!"

Eren writhed around in his mother's arms for a few seconds before she let him down. He then grabbed hold of Mikasa's hand and marched through the wooden gate.

"Bye mom! I love you!"

Both Eren and Mikasa waved at Mrs. Jaeger, who waved back, tearing up slightly. "I love you too, sweethearts! Have a nice day!"

And the two kids entered what had to be the worst level of hell.

It was pandemonium. There were kids hanging off the monkey bars by their ankles, some were jumping off the swings and somehow landing undamaged, and for some reason, a little girl was at the top of the slide eating voraciously out of a box of cereal.

Understandably, Mikasa's grip on Eren's hand began to tighten, but the boy next to her wasn't having it. Instead, his large green eyes began to sparkle wildly before he jerked away and ran into the throng. Mikasa sighed. She had seen this coming.

Eren ran around excitedly. He knew that Armin was around here somewhere, probably reading o something. Eren didn't know how to read yet, but he enjoyed the stories his friend had to tell. They were always good.

While he was lost in thought, Eren had forgotten to pay attention to what was directly in front of him. When he went flying, he landed hard on his elbows. All of a sudden, the entire playgound full of children went silent.

Eyes filling with tears, Eren looked behind him to see what he had tripped over, and couldn't believe what he saw.

A little boy, smaller than he and dressed in a green jacket and a once pristine white shirt, lay not far from him, glaring.

"You stupid brat, you got me all dirty!"

Eren, who normally would've manned up right then and there and fought this punk, scooted back. The boy across from him had eyes that looked as if they could pierce his very soul, and they were not being directed in a friendly manner towards him.

"I'm sorry, I didn't see you!"

The other boy scoffed, standing up. He wiped his forehead and was shocked to see blood on his hand.

"You bastard!"

The whole crowd of kids "ooohh-ed" at this, never having heard someone their age say a bad word before. The boy in the green immediately had their respect.

"First you get me dirty, then you make me bleed. Unacceptable." The little boy with the cold eyes advanced towards Eren's figure quickly before delivering a swift kick to his stomach. Eren felt the wind leave him as the small foot made contact with his abdomen. Within seconds, another blow was placed. He felt as if his whole chest were on fire.

This probably would've went on for some while had not two people come running to the center of the circle of children. Mikasa nearly tripped as she ran to stop the short child with the odd hair from hurting her brother, while a relatively normal looking woman with glasses grabbed the boy beating Eren by the hood of his jacket.

"Oh my goodness, it's only the first day and I've already got a fight on my hands! Come on, you're both going to the nurse, and then you'll tell me what happened. Connie!" she shouted over her shoulder, and an older looking boy came running over.

"Huh?"

"You're in first grade now, be a big boy and take these two to the nurse, and make sure they don't fight anymore."

"Yes ma'm!" The boy with the shaven head, Connie, did a strange salute to the teacher before turning to Eren and the other boy.

"Come on you guys, I'm Connie and I'll be your cap'n for this trip! Let's go."

Eren rose to his feet shakily. Normally, he would've fought back. But normally, when you trip over someone and you apologize, they forgive you, not try to kill you! What was green jacket's problem anyway?

Eren chanced a look at the boy who beat him up and let in a slightly audible gasp. He was half a head shorter than him! How had this happened?

From that moment on, Eren swore that the boy in the slightly too large green jacket was going to be his worst enemy. It would be a shame how long that promise lasted though.

A.N. It wasn't too bad, was it? This is my second SnK fic, and the first one I've put on here. This is also my first Kindergarten! AU and I'm a bit nervous about it. I have a feeling that I made some people a bit out of character, so any concrit would be lovely. And don't worry, there will be fluff! If there's anything people want to see in particular, don't be afraid to ask. Next chapter should be up soon too. Reviews make me smile, so please leave one?