Rosine enrolled in Class V of Thors Military Academy in March S.1204.
As she attended church in her hometown on a regular basis as well, she signed up as a sister at the chapel in Trista rather than joining a club at the academy. Sister Ornella of the Trista Chapel wondered why someone with a kindhearted personality like Rosine signed up at a military academy in the first place.
Throughout the games, she is seen talking to Instructor Thomas Lysander, who commends her on her diligent work for the Church. In March S.1205, Rosine is revealed to be a Squire of the Gralsritter supporting Thomas as the Second Dominion. They reveal themselves to only Rean Schwarzer, Awakener of the Divine Knight Valimar, to gain his support.
- Rosine resembles the eponymous heroine of Red Moon Rose in both name and appearance.
- The son of Keynes, Kay, has a crush on Rosine.