First appeared in volume 2 of the light novel. An 11-year old girl who appears as the cousin of Haruyuki.

Spoiler

Her true identity is the second generation Red King who replaced the first one and became the leader of the legion "Prominence." Her Duel Avatar's name is "Scarlet Rain." She is known to be an immovable fortress due to her Enhanced Armament which is a huge machine armed with large guns and missiles. Its sheer firepower means that she doesn't have to move in her spot. She pretended to become Haruyuki's cousin by using social engineering in order to get close to him. She did this to ask for help to defeat the fifth generation Chrome Disaster who possessed one of her legion members.