Olivia is an honor student at the academy. She was the protagonist of the original otome game. She is also the Saint of the Holfort Kingdom in the otome game.
She is by all means a modest girl who is very kind and gentle with people. She dislikes gambling. As a commoner, she's often shocked if not stressed on how most things around her are so expensive & luxurious.
Despite her kindness and modesty, she lacks a consistent amount of self-confidence, which most likely stems from how she is a commoner who attends a school that is dominantly populated by nobles who mostly look down on her.
Although she becomes more cheerful after befriending Leon and Angelica, her self-confidence deteriorates even further when she feels too dependent on them and questions her own self-worth.
(Source: The World of Otome Games is Tough for Mobs Wiki Wiki)