From Lilith Scanlations:
Barely making ends meet as a part-time delivery driver, Taeha’s luck takes a wild turn when he wins the lottery. But before he can even celebrate, a sudden accident knocks him out cold. When he wakes up, he’s back in high school—ten years in the past! As if that’s not bizarre enough, he soon realizes he’s trapped in a weird dating simulation game. The only way forward? "Find the love interests and raise their affection levels!" Can Taeha charm his way through the game and return to the real world?

Original Webtoon