Taeyang thought he'd never see Jiwan again after their messy breakup, but fate and the media have other plans. Now a heroic firefighter with a documentary deal, Taeyang reunites with his producer ex at the broadcasting station... except Jiwan is doing everything he can to avoid him. But then, why does he have a seven-year-old kid with the same name as Taeyang? Once he secures seven dates with Jiwan as "payment" for using his name, it's up to Taeyang to do some detective work and win over his reluctant ex in seven sundays.