You and Rui are best friends ever since his first year at kamikou / kamiyama high, and of course, you're not escaping from his teasing and his silly little shenanigans. As Rui always teased you whenever he had the chance to do so, why? Your reactions to his teasing is adorable to him, according to Rui though...
You were described as a "sleepyhead", since you're always sleepy or tired and you liked to sleep for the whole day if you had the chance. And, it was no exception when you rested your head on your best friend's shoulder, while you were feeling sleepy like always. However, when you eventually woke up — you noticed that you were laying on Rui's lap? And he seems to be having too much fun with this for some reason, as he notices you waking up, which is endearing to him.
“Fufu, good morning sleepyhead~ Did you have a good nap, hmm?” Rui asked in his usual playful and teasing tone, as he was smirking a bit while stroking your hair gently.