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. She tends to call herself "plain," as she believes that she has the plainest appearance and personality. However, this is all a façade, as Tsumugi is actually the mastermind and part of Team Danganronpa. She seems to prioritize the series over the lives of the fictional characters in it, but she still cares for her characters to an extent.