Responses
Okey this is what I'm guessing . So maybe the idol didn't go to school and it's his brother who went to school however seeing that they are twins maybe one day they swapped and idol went to school and met the mc . That's where it starts and despite the fact that he continued pretnding to be his brother and when his brother left he could no longer meet mc .. This his comment on pinning for his first love ?
I think the new twin is the one knowing the uke. The other one was secretly in love with his brother 's friend, that's why he is irritated each time he speaks about the past ( because he talks about his brother and not him)
What seems strange is the uke not knowing the twin but well...