Pretty cute. Aimi (light hair, popular guy) and Kaede (dark hair, ordinary guy).
So this aimi senpai is a jerk who goes out with anybody who confessed to him when hes single, under the condition that the partner should not interfere with whoever he goes with or whatever hes up to. So kaede took this chance to ask him out after aimi broke up with his gf. Surely enough, they are now dating. But having promised to agree to go out with him under those conditions, kaede came off as looking pretty nonchalant about aimi, especially after he didnt react much when a girl kissed aimi. This bothers aimi and without realizing, kaede has taken pretty much space in aimi’s mind.
Love Works in Mysterious Ways