Kalafina (カラフィナ) was a Japanese vocal group formed by composer Yuki Kajiura in 2007, mainly to perform theme songs for the anime Kara no Kyōkai, but later expanded to include many other theme songs for other anime shows and films including the Madoka Magica, Black Butler, Arslan Senki and Fate/stay night franchises. They released five albums that have charted in the top 10 for Oricon. They disbanded in 2018–19.

Source: Wikipedia (https://en.wikipedia.org/wiki/Kalafina)