„Whoa, a giant robot"
The Little boy stared at the enormous humanoid machine clad in violet armor, it's demonic, horned face right in front of him.
"Not exactly Shinji. It is a Bio-Mecha"
His father, Gendo Ikari, looked down on him and ruffled his hair. His expression didn't change but it never did, that's how father was.
"Dio…Ageha?"
He tried to repeat the strange words and his father's ruffling began more intense, making him squirm.
"Ahahaha Stop Papa"
He laughed trying to get away, finally his mother, Yui Ikari, looked at them and smiled at their hijinks.
"Don't worry about it Shinji. Just remember, when the big bad monsters will come we'll be ready and this Evangelion, will kick their asses."
"Yeah and Mommy built it so it can't fail!"
The boy enthused looking up at his mother who just smiled at that.
Steps echoed on the catwalk as another person joined them in front of the enormous weapon of mass destruction. Shinji's parents focused on the older man and left the boy to his own devices.
"Ah Professor, how did it go?"
The woman asked, addressing the somewhat elderly man. He chuckled.
"As good as you might expect it I guess, the old men…"
While adults talked the boy grew a bit restless and started looking around. He was a bright, happy child, therefore he was very curious about the world around him. Unfortunately there wasn't much to explore here, the catwalk ran through the room in straight line and ended on both hands with hatches. But he was also a good boy so he didn't even dream of leaving the catwalk through one of the exits. Instead he turned around and walked slowly to its edge to peer down. It was such a long long way down. The shaft was empty, as the maintenance personnel didn't fill it with the LCL yet.
He remembered that moment perfectly, and could easily recall every detail of it even many years later.
His mother turned her head and caught him with her peripheral vision, realizing he was not next to her like he should.
"Shinji get away from there!"
She barked the order, and he moved to comply but something went wrong. As he shifted his stance he felt his foot slip on something gooey. And then he fell.
"Shinji!"
His parents jumped forward, father faster than most men could, his hand outstretched. But he was too late, even as he threw himself down on the catwalk and outstretched his arm the boy was already beyond saving.
"Pour in the LCL QUICK"
His mother barked another order into her earpiece.
And then they could hear steps on the catwalk again, fast, faster than any human could do. A staccato of impossibly fast movement and a blur of black and blue shot past them.
The boy screamed as he fell his hand still outstretched to his father.
The blur jumped off the catwalk and hit the wall, then shot diagonally towards the opposite wall. Like a demented pinball it descended down the shaft, kicking off the walls as it moved.
The boy closed his eyes and screamed, he didn't want to die. No! NO!
And then he felt arms around him , and a sudden onrush of wind scattering his hair. Too scared to open his eyes he just snuggled to the warm body he could feel next to his own.
With one final jump and a loud thud under his feet the movement stopped completely. He could hear the sound of water being poured around him, and the screams of people up on the catwalk. But the sound he focused on at the moment was  acalm breath, and steady heartbeat of one who cuddled him.
The boy slowly opened his eyes and looked up. He was held bridal style by appeared to be a girl, her face devoid of any emotion. She seemed not much older than him.  
Her hair were a light shade of blue, and her eyes as red as rubies. Her face was completely expressionless, even father was more emotive than this girl. Her body was clad in some sort of one-piece suit. It was completely black except for pads placed on the sides of her chest which were green in color and the The top part of her collar as well as her back which were deep red.
"Rei queries: Are you unhurt?"
Shinji did not answer instead embraced the girl and started crying. The fright still gripping him tightly. The girl just cocked her head to the side and stared at him.
"I was so scarred Onee-chan"
He cried as he snuggled to her.
*Scene Break*
Shinji watched the girl in front of him, now that there was some distance between them he could properly see that she really was not much older than him, maybe a bit taller.
"Shinji, this is Ayanami Rei.  She is the one who will pilot the big robot."
His mother explained to her son who alternated between looking at the woman and the girl in front of him. His good manners kicked in and he bowed
"Nice meet you Ayanami-san"
The girl cocked her head again, her expression not changing.
"Rei dismisses: There is no need to treat Rei so politely. Rei is a combat clone, part of the base's inventory. Rei should not be treated as a human being."
The boy blinked confused by both the strange way the girl talked and the strange words she was used. His mother sighed but didn't address girl's odd attitude.
"Nevertheless Rei, protocols are important if you want to properly communicate with people around you"
The girl shifted her attention from the boy to his mother, and nodded.
"Rei acknowledges"
She shifted her attention to Shinji again and bowed politely.
"Nice to meet you too Ikari-san"
"Now, how about we continue our tour Shinji?"
The mother smiled at her son who nodded eagerly.
"Rei could I ask you to look after my son so he won't get into more trouble?"
The woman addressed the girl who nodded and stepped forward, she stood next to the boy and took his hand in hers.
"Rei clarifies: Limited physical contact and movement restriction will ensure that Ikari-san will not be able to wander around unsupervised"
The boy didn't exactly understood what she was talking about but nodded happily. This girl saved his life so he had to be nice to her.
*Scene Break*
"Cafeteria is that way. I bet you two are hungry from all the walking"
Mother addressed the boy who dutifully looked in the indicated direction but something down the othercorridor caught his attention. There was an observation deck with a large glass window there that showed a large portion of the Geofront.
Shinji's curiosity got the better of him again and his steps inadvertently carried him towards the window. And then he almost yanked his arm out of its socket.
He turned around and saw that the girl who held his hand did not make a move to follow him. She just stood there, as unmovable as the mountains, her grip gentle yet firm.
"Rei reminds: Wandering unsupervised is forbidden"
"But…"
He tried to defend himself but just didn't know what to say to the girl.
His mother chuckled and looked down at the girl.
"It's okay Rei, go with him and let him watch the Geofront, when he gets bored bring him to the cafeteria, okay?"
The blue haired female looked up and nodded.
"Acknowledged."
The boy thanked his mother with a smile and dragged the older girl away towards the curious sight in front of him.
*Scene Break*
"Ahahaha you did this bento all by yourself?"
His mother laughed warmly as he unpacked the box with food.
"Aunty helped me but I did most of it!"
He smiled proudly, and then squeaked as his mother hugged him.
"Aww Shinji, will you become Mommy's wife?"
The boy struggled to get away as she cuddled him.
"Mom! I will become a husband! A boy can't be a wife!"
"Really?"
Professor Fuyutsuki chuckled into his meal stealing glances at Gendo who returned them with a glare.
Finally free to enjoy the results of his hard work the boy sat down and opened the bento. Both of his hands free now. The girl sat next to him, methodically cleaning her tray off the food she was served. The boy glanced from his bento to the plain, unappetizing food the girl was eating.  Most of the food provided by the cafeteria was previously frozen and only when it was to be served the cooks reheated it.
"Umm… Ayanami-san?"
The boy asked shyly. The utensils the girl was holding stilled and her eyes focused on him again with laser-like intensity.
"Would you… would you like some of my bento?"
He asked shyly indicating the food he had prepared. The girl glanced to Shinji's mother as if to ask for guidance and Yui smiled.
"It's bad manners to refuse"
She explained with a gentle smile. Rei nodded and turned to Shinji who got somewhat used to the girl's strange behavior and was waiting for her reply.
The girl nodded at him.
"Rei accepts"
The boy smiled happily and took  a piece of chicken from the box with his chopsticks. Holding his other hand under the piece of food, making sure it wouldn't fall to the ground if something happened. He brought the offering close to the girl's face.
"Say ahh"
The girl blinked but dutifully opened her mouth.
"Rei says: Ahhh"
She said and the boy inserted the morsel in her mouth. She began chewing on the delicacy, slowly and methodically she worked her way through the meat and finally swallowed it. Then she cocked her head to the side.
"Rei expresses confusion: Rei was not aware of the fact that sugar is added to chicken during its preparation"
The boy grinned.
"Sugar is good, it's sweet."
He explained to her, expressing the love for sweets present in all children. The girl cocked her head to the side and thought for a moment.
"Rei acknowledges: Sugar is an easily digestible source of energy, it is acceptable to consume certain amounts of it in order to provide one's body with emergency fuel"
She nodded at the boy who just looked at her confused. Wasn't eating sweet things done for the sake of sweet things themselves?"
*Scene Break*
The boy stood next to his father, his mother and the strange girl standing opposite of them.
"I'll see you later Shinji, Mommy has some more work to do."
"Okay Mommy. Ayanami-san I had fun playing with you, I hope we meet again"
He addressed the emotionless girl standing next to his mother. She blinked at him, and suddenly he realized that this was the first time he has seen her do that today. The girl remained silent for a couple of moments. Shinji's head lowered a bit, apparently his sentiment was not shared by the girl.
"Rei…"
She spoke quietly and broke off. The boy perked up at that.
"Rei…  expresses hope: Rei wishes to see you too soon."
She told him, her voice slower, less sure than before. The boy giggled and run up to her, hugging her.
"Yeah let's play some more when we meet again"
He waved at her as they departed. Ikari Yui had an enigmatic smile on her lips as she glanced down at the girl. She rose her hand and starred at it for a moment before emulating the boy's behavior by waving at him.
"Well Rei, I hope you had fun."
She said and both turned around, heading back into the NERV headquarters.
"Rei expresses uncertainty: Rei is not sure what one would consider fun… However Rei believes the interaction with Ikari Shinji was not a complete waste of time."
She finally stated, making the woman next to her smile.
"Well time to return to tests. We'll be using 10 A-Level androids this time. Live ammunition and grenades."
The girl nodded.
"Try not to destroy them all in one go, okay?"
"Rei expresses confusion: Why should Rei underperform?"
"Because, Rei, those things cost a lot of money and we Do have limited budget"
The girl walked silent for a couple of moments and then nodded.
"Rei accepts the explanation: Rei will attempt to limit the number of destroyed androids to eight within the first 5 seconds of combat."
Yui could only shake her head sadly.