Tsumugi is a self-described plain-looking girl of a rather tall height and fair complexion. She has knee-length teal-blue hair parted in the center, straight and smooth at the base and gradually splitting into waves near the tips. Her eyes are large, round, and a soft teal-green color. She wears round, rimless glasses with white temples. Tsumugi is an honors type student who speaks in a docile and gentle way, but she becomes very passionate when she talks about her favorite series or cosplays.