Kyrie (pronounced /ˈkir-ē-ˌā/) is a supporting character in Devil May Cry 4. She was born and raised in Fortuna, is the younger sister of the leader of the Order of the Sword's Holy Knights, Credo, and songstress for the Festival of the Sword. Kyrie is the childhood friend of Nero, as well as his lover.
She carries a necklace that was given to her by Nero at the beginning of the game as a present during the festival.
The love between Kyrie and Nero seems to have started before the events of Devil May Cry 4, but their love is used as a major plot point on several occasions during the game.