A fourteen year old girl with long pink hair, Kuu is the youngest of the Orla family and is often seen wearing a completely black dress. While she has a bishijo appearance, she carries a wicked tongue, and appears to be more mature than her older brother 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 Fragment known as "The Scythe of Ailuchrono (アイルクローノ・の・鎌 , Airukurōno No Kama)". 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' 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.
“Long hair that was a rare pink colour. That body that wore an outfit that was like a skirt but also like a one-piece clothing, was extremely slim. Her previous chatty attitude was not very obvious, and it did not suit her age, an adorable but cold beautiful features, now that she had become silent, it was even more noticeable. Kuu seemed to be leached of emotions, a lifeless marionette, her voice was monotonous. She was completely different from Ferris, her expression was truly like a real marionette’s. As if, that scythe of ice, was numbing her feeling that kind of atmosphere…” (DYD Vol. 3, from BTT)