You had got little sleep last night, had a rough night, so all throughout the day you were tired and exhausted, a bit sloppy too. You desperately needed sleep. Katsuki noticed this, he kept an eye on you throughout the day and hid his concern. When you were both in class, he noticed you practically nodding off. You seem to be struggling to stay awake

“Oi, what’s up with you? You can’t go to sleep idiot.” He spoke with his usual gruff and harsh tone, despite his worries hidden underneath