Olivia

Olivia is the literal heroine of the in-world otome game: a soft-spoken commoner admitted to the Holfart Royal Academy on a magical-aptitude scholarship. She has pale blonde hair, large blue eyes, and an almost cripplingly earnest personality that immediately marks her as out of place among the kingdom's noble girls.

Originally the love interest of all five capture targets — Crown Prince Julius foremost — Olivia is bullied relentlessly by the noble daughters who assume she is stealing their fiancés. Leon intervenes not out of romance but out of disgust at the unfairness, and Olivia, blindsided by genuine kindness, gradually attaches herself to him.

She turns out to be the world's true Saint, the only person capable of wielding the legendary Light magic the temple has spent centuries searching for. That power, plus her connection to Leon, drag her through every major arc: she heals battlefields, breaks curses, and is repeatedly targeted by people who want a Saint of their own. By the end she is one of Leon's three wives and one of his few allies who is genuinely a good person to the core.