Heartbreaker!

Lee Lozer is a senior-year transfer student in a prestigious school called 'the Eden of Geniuses', Lockhart High. Considered a bottom feeder by those around him, he's talentless, fat, and ugly; an eyesore for the elite student body.

After discovering the prettiest girl in the school, his crush, Ria Goodgarden, and star soccer player, his bully, Eric Graves, kissing on the rooftop; he's pushed down the staircase to his death.

Given a chance to be reborn with a new lot in life by a mysterious being, and failing once already to change that chance, he's given the title of 'Heartbreaker':

"To be reborn as a girl and to help his past life find true love."

This would be simple enough if it weren't for the mysterious being adding in an extra caveat:

"You have to find true love as well too!"