Levi glanced warily down to the small child standing beside him. The little cutie looked back up to the battle worn face of his caretaker for the day. Levi awkwardly shifted his feet and kicked at a rock as the child stood beside him, just watching him expectantly. Levi personally didn't like dealing with kids, the fifteen year old trainees were the youngest he could even think of tolerating, but when a friend of his, Carla Jeager, came to him begging for help, he reluctantly agreed to watch her child for the day.
"So..kid," Levi hesitantly said to the child, "Your name is Eren, right?"
Eren nodded a little too eagerly, causing his dark brown hair to dishevel and splay across his face messily.
"And your name is Levi," Eren cheerily piped up, "You're the corporal of the Survey Corps!"
"Indeed I am."
Levi still felt awkward in the presence of the (in his opinion) way too cheery six year old. On the other hand, Eren looked like he was right at home, standing next to Levi in a pretty field, clutching his over sized stuffed dog plush. Levi noticed the two pink buckles wrapped around one of the dog's legs, oddly similar to that of a military uniform. He plucked at them curiously.
"Say kid," Levi's voice had a questioning tone to it, "Why's your dog got these straps?"
"Because!" Eren's face looked up at Levi's almost dumbfounded, since to Eren, it was quite obvious. "It's supposed to be like the one's on the military outfits!"
"Yeah I got that, but why?"
"Because!" Eren was growing agitated of this older man's obliviousness to the obvious. "I want to be a soldier someday, just like you! I'm gonna join the Survey Corps when I'm older!"
Levi shook his head and removed his hand away from the buckles. It made him sad knowing a small child looked up to him, he was far from a role model. It made him even more sad knowing a child was even thinking about wanting to join the military at such a young age. He knew that Eren's mother would have a heart attack if she knew he planned to join the Survey Corps.
"You're too young to be thinking about that kind of stuff, kid. Being in the Survey Corps is complicated and takes a lot of bravery. Besides, I don't think your mother would be too happy with you joining the military at all."
Eren's face grew red in anger at the words of Levi. He stomped his feet in a desperate effort to express his anger without hitting Levi in the leg, which he knew would get him in trouble.
"I am brave! Just you wait and see! When I'm fifteen, I'll be part of the Survey Corps. And I don't care if Mom doesn't want me to join the military, she can't stop me!"
Levi was amused at Eren's temper tantrum and let a small smirk show on his face before answering.
"You sure you're brave, kid?"
Levi was half expecting the kid to turn a bright red and run off, the other half expecting the kid to smart mouth him back. What Eren ended up doing, did indeed surprise Levi, something that usually never happens.
"I am brave! And I'll prove it to you!" With that, Eren ran forward and raised his foot as far back as he could before sending it smashing into Levi's shin. Levi was torn between having respect for the kid, being angry, and being amused. Of course Eren's attempt didn't actually hurt Levi, but he was still not quite happy that the child had disrespected him like that.
"I'll get you for that, kid!" Levi's tone suggested amusement so, of course, Eren was not scared but instead ran off giggling, starting a game of chase with Levi.
"You gotta catch me first!" Eren giggled while looking back over his shoulder. Levi chased Eren around, making sure to slow down his pace so Eren had a false sense of success, until he sped up and wrapped his arms around Eren's torso, lifting him high in the air. Levi twirled the child around as his soft giggles filled the air along with even Levi's childish giggles. Levi wondered what his comrades would think if they saw him like this, totally out of character and laughing like a little kid. As he placed Eren down, the little cutie wrapped his small slender arms around Levi's legs, closing his eyes and humming a soft song that Levi vaguely recognized. Levi let his hands curl around the child's back, completing the hug. Eren pulled away and reached out for Levi's hand. Levi tentatively took the child's hand and he pulled them down towards the ground. They sat side by side in the field grass, a light breeze swaying the world around them. Levi's thoughts began to wander and he kept thinking about how it wasn't fair for such a nice kid to grow up in a cruel world like this, especially a kid that wanted to be a soldier at the age of six. Eren was still humming softly and eventually it drew Levi out of his deep thoughts.
"What is it that you're humming?" Levi asked curiously.
"You are my sunshine!" Eren smiled a wide toothy grin. "Mom taught me it. It goes like this: You are my sunshine, my only sunshine. You make me happy when skies are grey. You never know, dear, how much I love you. Please don't take my sunshine away!"
"You know," Levi looked the kid right in the eyes, admiring the youthful look in his eyes (was it pure happiness that you lose as you get older? or maybe something else, a kind of thing that only children see about the world), and patted him on the back softly, "You're alright, kid. You're quite alright."
"Thank you, my sunshine, Levi!"
Eren popped up and sat down in Levi's lap, curling into him. He let his eyes slowly close and Levi wrapped his arms around him. And so they sat there, the wind and presence of Levi slowly rocking Eren to sleep, in the middle of a field in the corner of what could only be described as Hell.

Levi was standing in front of the Jeager threshold. Carla had sent for him, apologizing profusely as she opened the door.
"Hello, Levi," She apologetically greeted, "I'm so sorry to do this but Eren won't stop talking about his sunshine Levi."
Upon hearing this, the corners of Levi's mouth turned up just a little bit into a small smile. Nothing could quite make him smile like that stupid kid. The door opened wider and Levi saw two wide blue-green eyes before him, gazing up at him excitedly.
"My sunshine Levi!" Eren cooed, wrapping his arms around Levi's legs.
"Hey, kid," Levi replied softly, ruffling up Eren's hair. "It's fine, Carla. Eren is a real joy of a kid."
She smiled sincerely, a warm glow radiating from her. She could tell how much the two had bonded, it was the third time this week that Eren had spent his afternoon with Levi. He begged for it to be everyday but with Levi's busy work schedule it wasn't very possible. Levi nodded to Carla in polite farewell and turned and left with Eren, hand in hand. They walked to their field and lazily picked flowers as Eren told Levi all about his day. Levi listened intently and made frequent comments. Normally he was quiet, but this kid just brought out the voice in him. Eren asked about Levi's day but Levi avoided telling him in exact detail, to spare him of the cruel happenings outside the wall. How had Levi's day been? Awful, he had watched a couple of trainees he couldn't get to in time be crunched between the teeth of a titan. He had to listen as they called, terrified, for their parents. Their last words had been echoing in his head all day and he simply told Eren that his day had been fine, a bit boring actually. Eren had noticed Levi seemed a bit sad about his day so he ran up and poked Levi in the stomach, initiating a tag session, trying to cheer him up. Instantly Levi perked up and ran after Eren, laughing and picking him up and swirling him around like he always did. It was Eren's turn to chase Levi around and so this continued on as echoes of their laughter filled the air and for once, this hell didn't seem quite as bad. Finally, they sat next to each other, panting and out of breath from the chase. As they rested, Levi gazed out into the horizon as Eren crafted a flower crown carefully out of the flowers he had picked earlier. There was all kinds of flowers, from blue to red and it was quite beautiful. Eren reached over and placed the crown on top of Levi's head, leaning in to hug him afterwards. He curled up in Levi's lap as exhaustion took control of his little body. He soon dozed off and Levi swept the hair out of the sleeping child's face delicately.
"Goodnight, my sunshine," Levi softly whispered.

Levi had never found himself wanting kids or a close family even. He didn't even had what you could quite call friends, considering most of the eligible candidates became titan food at some time or another. But then little Eren came along and suddenly he felt like Eren was the closest thing he had to family. He loved the child like it was his own, even though he knew Eren had two loving parents of his own. He could not bear to think about the future when Eren would turn twelve, considering he would probably decide to join the military. But it was not his choice, but Eren's, and it was six years away anyways. Eren was his little sunshine who made him flower crowns and genuinely seemed to care about how his day was. He was the one who reminded Levi that this cruel world they lived in was filled with wonderful miracles who deserved more than living inside a glorified cage. He was the one who reminded Levi why he even tried to keep fighting as he existed the walls and fought on the monstrous titans that lay beyond them. He vowed that he would slay all the titans so Eren could run his little heart out and see those oceans he talked about and run free, safe of any danger. Eren shared the same love for Levi. He thought of him as more of a father than his blood related one, even though he did still love his father. He admired Levi and looked up to him, wanting to be just as brave as him someday.

Levi normally wasn't surprised by things but nothing could have prepared him for what was to happen on that day. An aberrant titan had approached the walls. It was unlike any titan they had ever seen before; it climbed up the walls with ease like a squirrel up a tree. As it leaped from the wall, to Levi's horror, it landed right near the Jeager house where Eren was currently coloring, waiting for Levi to come take him to the field. As soon as Levi caught sight of the horrible monstrosity near his boy, he was off like lightning. He moved quicker in his gear then ever before, driven by an unseen force. He was there, standing by his comrades with a shocked face, and the next second he was gone, racing to protect Eren. Hearing the commotion, little Eren wandered out of his house to find himself face to face with a titan, who smelled of foul, rotten flesh. Levi arrived there just as the titan picked up little Eren into his massive fist. Levi sliced the titan deeper than he, scratch that-anyone, had ever sliced before. But an aberrant was unpredictable and as soon as it had realized Levi was approaching, it had cast Eren out of his hand and crashing into a nearby building. Levi watched with horror as the little boy's body thudded onto the dusty street. Levi was over and by Eren's side within seconds. He cradled the limp boy in his arms, whispering to him telling him it was going to be okay, even though he knew that Eren was already gone. A single tear dripped from his eye and rolled down his cheek, marking the first time Levi had cried in years. Levi was filled with a burning rage so powerful it could fuel a voyage to Pluto and back. He would kill all those good for nothing titans who didn't even deserve the essence they were given; he would kill all those titans for his beloved little Eren, the one who taught him the meaning of life, his little sunshine. And as a young man, aged with battle and pain, cradled a young boy, filled with sunshine and beautiful days, a song began to play deep within the young man's head. It was soft as first but gradually got louder as his tears began to fall heavier. It was the sound of a little child singing:
"You are my sunshine, my only sunshine,
You make me happy when skies are grey
You never know, dear, how much I love you
Please don't take my sunshine away"
"Please don't take my sunshine away," Levi whispered, kissing Eren's forehead.