Living an unremarkable, failing life as a long-term unemployed adult, Kang Da-hye gets pushed out of a permanent job offer once again—only to suddenly regress back to her second year of high school. Thrilled for a fresh start, she vows to study relentlessly, get a perfect score on the college entrance exam, enter Korea University, and land a great job right upon graduation. However, her hyper-focused study routine is constantly disrupted by two ridiculously handsome boys. One is Jung Eun-sung, the future lead singer of a hit idol group who regressed alongside her, and the other is Seo Jae-gyeom, her former secret crush and the illegitimate son of a wealthy family. As both boys start vying for her heart with passionate confessions and desperate pleas, Da-hye finds herself exasperatedly shouting that she is far too busy studying for romance.