Wait a minute that classmate really looks like jaeyi is that his brother?

The brother is 29, Ideum is 26. The guy from the past is supposed to be in the same class/age bracket as Ideum. Altho the girl said the bro was sickly so he could have had to repeat a grade. I don't think he is the same guy.

I was thinking this! But then I saw the age difference. It says his brother is 29 but Ideum is 26 and the guy he had a crush on was in the same class as him. Unless it’s a mistake on the age thing?