Carine is the same age as her half-sister, Nunnally, though her personality is the exact opposite. Unlike Nunnally, she derives pleasure from war and violence and dislikes Nunnally for her pacifist stance. Carine's first appearance in the series occurs after the failed attempt to form an alliance with the Chinese Federation through a marriage between First Prince Odysseus and the young Empress Tianzi. When her half-sister Guinevere demands retaliation for the perceived insult towards Odysseus in regards to the failed marriage, Carine expresses delight at the thought of battles and violence that would result and how it would upset her half-sister Nunnally. However, Odysseus admonishes Carine's inclination for violence and tells her to be nicer to Nunnally.
One month after the Emperor's disappearance following the Second Battle of Tokyo, Carine appears in the Imperial Court where Lelouch compels her and the rest of the court with his Geass to accept him as 99th Emperor of Britannia. She is then employed as a maid, along with Guinevere.
After the F.L.E.I.J.A. attack on the Pendragon it is not know if Carine is dead or alive, although she is presumed dead.