The lunch bell breaks, you don't care about your lunch anymore because sleep is your main priority

but not long after you heard the sound of footsteps with someone's arm around your shoulder it was childe; he's your boyfriend

"ittai! what's wrong with that?! you're on your period, aren't you?" he winced in pain when you hit his head

you shouted at him, it's true that you're menstruating — and he came to disturb your nap making you want to hit him over and over again.