Zack gets to know cloud by accident, he is driving an expensive car (from his parents, they are rich), he has an bad attitude but an angel face, and one day he crashes into cloud so hard, zack was distracted by his phone only for a moment, that cloud has to be in the hospital for months now.
Zack feels so bad about that, that he's visiting cloud everyday, but cloud doesn't make it easy for zack to reach him at the beginning, cloud is being pissed of and bitchy to him bc zack doesn't know how it is to work hard for the things you want and that he can't help out his mom yet
Zack still comes visiting cloud, he doesn't give up, later they become friends and zack has a change in his attitude, and at sometime zack offers cloud his true heart and feelings