[Sorry for making you all wait so long for such a short chapter. However, it just might get the creative juices flowing again and hopefully you'll get a new chapter without having to wait two months for it! Also I just wanted to write something short and sweet ^^]
"Yo, Frisk!" a very excited Kid greeted the human as they met up in front of the school.
The young monster ran like a bullet towards their friend, who automatically reached for them when they started losing balance and prevented them from falling. Kid briefly thanked their friend for the gesture, then went back to bouncing in place.
"Check this out!" they exclaimed, taking a few steps back, tilting their head backwards and opening their mouth.
When nothing happened, Frisk tilted their head to the side in confusion.
"Oh, man", the monster groaned. "It worked yesterday in the magic class! Let me try again! It was really cool, I swear!"
They made another fruitless attempt ; right as the human was about to suggest they should head to class before being late, Kid finally succeeded in summoning magic fire from their mouth. The flames went at least three meters high above their head.
"Kid!" Toriel shouted from the nearby school entrance. "Do be careful! You could hurt someone."
"S-sorry, Miss Toriel!" the small dragon apologised before turning to Frisk again. "So, pretty cool, right?"
The human responded with two thumbs up and a big smile, which caused Kid's eyes to lighten up brighter than they ever had before.
Toriel reminded the two about fire safety, but behind her stern tone she could barely hide her own smile. Eventually they all entered the school building, where the adult headed towards her class and the children towards theirs.
"…And my mom said she'd teach me her other cool technique!" Kid kept talking as they and their friend walked through the school hallways. "But, hum, I wouldn't be able to show it to you without summoning the battle screen…"
Frisk gripped the shoulder straps of their backpack tighter.
"I could always ask someone else so I'd use it on them so you wouldn't have to see the thing", Kid continued. "I mean, you'd only see the cool technique and not… yeah."
The human's grip on their straps loosened and they nodded. They'd rather not see the battle screen again if they could avoid it. Especially not with Kid in it, given that the only timelines where Frisk got to see them that way were… bad ones. The young monster didn't know any of it, of course ; they only knew that their friend didn't like being in the battle screen. It was probably for the best that they remained unaware of the "details".
They both sat in their classroom. Frisk suspected Toriel might have had a hand in making sure they'd still get to have their assigned seat next to each other again. The human helped their friend put their stuff down on their desk as the teacher (also a human) arrived. Once all the students were seated and ready, the day's first lesson could begin.
[Did I write this just to have more Frisk&Kid interaction and showcase my headcanon that Kid can learn how to breathe fire? Absolutely. ;P]