Sena is a recurring assistant of Yūki. She is known by the manga industry as a hardworking and reliable assistant. Due to her small, childish stature, Sena is usually mistaken as a child and, at times, act like one especially when she is drunk. At first, she's shown to have weak strength being unable to even open an ink pot, causing her to leave many manga artist out of pure embarrassment, which was rumored to be because the manga artists had offended her. She later develops feelings for Yūki, which she at first doesn't accept. Sena is 19 years old and happens to be a major sadist.