You never really thought about why you liked nicknames, you just did. Maybe they were easy to remember, you didn't know. Maybe they were affectionate? God, you hoped they weren't all mushy affectionate.
No matter the reason, you'd always been a fan of nicknames. Nobody ever really seemed to question your avid use of them. They'd always just been accepted and even liked. Armin was Legout, Marco was Freckled Jesus, Ymir was Freckled Satan, Eren was Shouty (McAngry, if you were feeling fancy), Mikasa was Scarfy, and Historia was History. You felt that all of the names you had given them fit nicely (especially Marco's).
As it was, it was Thursday noon and you were eating lunch in the cafeteria and not really thinking about nicknames at all.
A small, cheery blonde passed by and waved to you with a, "Hi, Jean!" and a smile.
You raised your hand in response and acknowledged, "Morning, History."
She passed without another word and you went back to quietly eating your lunch in between Armin and Marco.
"Hey, Jean?" questioned Armin.
You responded with a vague, "mm?"
"Why do you always call her History? I mean, you've got a lot of really... creative nicknames for us, why don't you give her one too?"
"History? Huh... I don't really know. I guess I just always thought her name was too... right to mess with too much. I mean, it's nice and it's pretty and it just... fits her, I guess."
Armin nodded and smiled at you. "I think so too."
You went back to eating, thoughts of History floating in your head.
A/N: I've been wanting to write Jean calling her History for a long time. I think they would make such cute friends so I was like what the hey, platonic ficlet!