A fourteen year old girl with long peach colored hair, Kuu is the youngest of the Orla family and is often seen wearing a completely black dress. While she has a bishōjo appearance, she carries a wicked tongue, and appears to be more mature than Sui, often complaining that she has to look after him, and may never to be able to become a bride because of this. Like her brother Sui, she wields a Rule Fragme known as "The Scythe of Ailuchrono. The artifact is in the shape of a large scythe, and rapidly increases the wielder's strength and speed, allowing Kuu to easily match up to Ferris's speed. The blade also has the ability to freeze anyone who comes into contact with it, and Kuu manages to use this ability to stop Sui from bleeding to death. As a side effect, the artifact "freezes" the wielder's heart as well and Kuu will lose all her emotional capacity when she's wielding it.