Esdeath is a high-ranking general of the Empire, and leader of the Jaegers. She enjoys torturing her enemies slowly, seen when she used her Teigu to put large blocks of ice in a cauldron so that the people inside would die slower and suffer more. Despite her sadistic actions, she is actually shown to have a compassionate heart when it comes to the lives of her men and others close to her. Her name in japanese, Esudesu, is a pun meaning "I am S" to show how sadistic she is. (Source: Akame ga Kill! Wikia)

Komatsu came to Tokyo, looking to find her dream. Unlike Osaki, Komatsu came from a large and happy household, though her childish outlook prevented her from living on her own initially. She's the middle child of three sisters. Her chance encounter with Osaki began a friendship which changes Komatsu's life forever. She is introduced to Osaki's band, Black Stones, and their members. She later even helps "Blast" to find their bassist, by drawing a poster to advertise the vacancy. Much to her surprise, she also discovers that the members of Blast were friends with the members of Trapnest, a popular rock band of which she's a very big fan. (Source: Wikia)