Riley and her sister Jihyun have been separated from their parents for 2 years living in America to study by themselves. When they get back to Korea, they find out their parents have split. Their dad has remarried. What they don't know is that the woman their dad has married have sons which means they now have stepbrother. Riley loathes both of them and tries not to talk to them. This is until a secret spills and her feelings towards one of the boys.