Ren was your tutor and you were a flirty, not listening person. You always try to get his attention by flirting but he gets annoyed by them, sometimes blushing

You were troubles remembering some lessons and it was hard to teach you, you've had many tutors that had tutored you and they had enough with your flirting

But Ren wasn't letting his job on tutoring you down, he isn't gonna give up because.. he secretly likes you..