Left one is named Diamante, (Diamond in Italian!)
Right one is named Ala, (Wing in Italian!)
Summary - Diamante loved nothing more than her sister. One day, her sister Ala went missing, and returned to Diamante as an angel. Diamante now goes around killing people who seem like they would have killed her sister. She works for the mafia, even with Ala's protests. Ala is the younger one of the twins but still gives better advice. Art not mine!!