Very very close scenario:Meteor Garden --- She falls for second guy, but he has a GF ... lead guy likes her, she starts dating him, then second guy comes back and she leaves the lead to be w/ second guy ... then she realizes she loves lead guy, so breaks it off ... they go back and forth until she finally chooses lead guy.
Not exactly:Summer's Desire --- She is w/ first guy, they separate, she starts dating second guy ... first guy returns, they go back and forth ... until she makes decision towards the end .... But we don't know who she'll choose until the end..... She uses both guys!