I'm Done Being Your Best Friend

"Siena's refreshing counterattack and fateful love story after a lifetime of being just a sidekick!" After a life filled with misfortune and standing on the sidelines, Siena faces death—only to discover that her only friend, Daisy, had always seen her as nothing more than a mere sidekick. Realizing she had been manipulated and used throughout her entire life, she is struck by despair. But at that very moment, a miracle happens—Siena returns to the past, to the day she was eighteen!

(Source: NaverWebtoon, translated)