True Beauty (2018)

Finished: ran from 2018 to June 2023. Lim Ju-kyung hides behind flawless makeup after being bullied over her looks, and the romance works because Su-ho, the first to recognize her beyond the makeup, is the one she can be honest with. The Su-ho and Seo-jun rivalry gives it a proper love triangle, and the story follows the leads past high school into their twenties, so you get the payoff rather than a graduation fade-out. It is long, which is the point for a binge. If you have only seen the 2020 drama, the webtoon goes much further.