Fumio is only my favorite OC ever. She's about 15 here, and her maternal instinct goes into overdrive when she's around Atom.
"Hey, Atom…" Fumio said, blinking. "You seem like you've matured a bit."
He smiled, tilting his head. "As a robot, I'm not sure I can mature the way you're implying…"
"Learning from your mistakes. That's maturity. You've made mistakes, haven't you?" Fumio asked lightheartedly. "Or… is it against your nature to do so?"
Atom looked down, contemplating an answer. "I believe… that I've made a lot of mistakes."
"That's your humanity." The girl laughed. "It's okay, you should feel happy about your mistakes. They've made you a better person."
Atom beamed at the praise.
"But, you know, Atom…"
His smile fell into a curious pout.
"Maybe it's good that you don't mature the same way humans do… Hey, listen." She crouched down on one knee, at the robot's eye level. "You be careful with all that maturity, okay?"
He smiled again at her playful tone.
"Maturity… is the loss of innocence, naiveté. Once you lose those things, you can't gain them back, human or robot. Protect your innocence, Atom… don't lose your faith in the world. Don't… grow up so fast."
"Fumio-chan, you worry too much." Atom giggled, surprising his friend. "Just because I don't talk about these things… doesn't mean I don't think of them!"
Fumio gave a flustered smirk, relaxing her shoulders. "Ah, yeah… I suppose you're like that, aren't you?"
Short oneshot is short. I was planning on continuing but that was two years ago and that train of thought is long gone.