FictionJunction YUUKA is a collaboration project between ???? (Yuki Kajiura), who handles the composition, arrangement and keyboard playing, and ???? (Yuuka Nanri)), who sings. Kajiura Yuki is a renowned music composer who has created the music for a variety of anime series such as .hack//SIGN, Noir, Mai HiME, Mai Otome, Tsubasa Chronicle, Madlax, etc, as well as several video games, including the 2nd and 3rd installments in the Xenosaga series. She has also collaborated similarly with ????(Ishikawa Chiaki,as See-Saw) and Kato Asuka (FictionJunction ASUKA).
Yuuka Nanri is also a ??(seiyuu,voice actress) for Japanese anime.