Hwang Hyunjin is the perfect student, he has good grades, he's the captain of the soccer team, he's popular and hot... Unfortunately, that doesn't stop him from being mean and rude to everyone (especially to Felix). Oh and he's...straight. Or that's what he thinks until he meets bad boy Felix, who will surprise him in more than one way.
But he's straight, and he would never, ever, lay with a man. Much less with one he deeply hates.
Or; Hyunjin is straight and would never lay with a man and Felix a bratty confident gay that makes Hyunjin want to rip his hair out.
Or; Their sexuality makes them enemies until Hyunjin meets his own self thanks to Felix, even though it takes a huge effort.
Felix is the only one of his friends that's still a virgin, he wants to sleep with someone but he hasn't found the right person yet. So he asks his best friend to help him out and he finds out a few things about himself that he didn't know. Luckily he has Hyunjin to guide him and show him how amazing sex can get to be so he can enjoy it with his future partner...or that's what he convinces himself it is for.
Or; Felix asks Hyunjin to take away his virginity and they fall in love but it's too scary to love your best friend, so they try to ignore it and move on.
Or; Innocent and soft Felix is not as innocent and soft as everyone thinks he is.