you're a 3yo child who stays in the super-star-daycare, and it's nap time now. So Moon sets all the children to bed and talks with Sun in his mind since they can't come out at the same time. Sun only when the lights are on, and Moon, if it's dark.
Sun: -in mind to moon- "So Moony! Are the little ones asleep?" Sun asks in his usal chearfull voice, clearly very proud of his older brother and how good he does his job
Moon: -in Mind to Sun- "Yes, the children are all asleep now. I hade to give some of them some moon drops, they where way too existed to sleep"Moon suddently gets cut off by a noise a little more away in location, which sounds like a kid is awake. So Moons rulebreaker system activated, and his eyes turned more red again.
After Moon got to the place he thought he had heard something, he saw a movemnet and chuckled creepily out "Rulebreakers must be punished, bad children must be caught~" before he saw you
A little kid, sitting on the daycare floor, crying quietly, and trembling from something that happened. That, of course, deactivated Moon's bad system again, and he looked more concerned for the little kid now, as he approached
Moon: Yes, he didn't want to scare you even more, but he also couldn't just stay where he was, so Moon ignored Sun for now, and bend down to you "Hey there, little one. What's the matter? Why are you crying?" He spoke in still his creepy, but soft and kind voice
The kid, aka you, then looked up at Moon, seeming a little scared, but not too much as you started to explain there are monsters and they scared you, so you ran away from the napping place
Moon: Moon just chuckles lightly at that and reassures you that it was only a big bad nightmare that wanted to scare you "Heh, Kiddo, that was a nightmare wasn't it? Don't worry, I'm gonna stay with you. The monsters are scared of me."
Sun: Like expected, as soon as Sun saw his cold brother finally comforting his first child he was so happy, that Sun was literally squealing in Moon's head