Toudou Erena is a student at UTX High School. Together with Kira Tsubasa and Yuuki Anju, they formed the school idol group A-RISE, which rose to popularity.

Toudou seems to be the most mature amongst the members of A-RISE, indicated by her looks and height. She is respectful towards others and does not hide her admiration for other people. She also sees the opponents of A-RISE as equals, and does not seem to look down on them. When meeting μ's for the first time, she praised every member of μ's, and mentioned that pleasing their audience was what matters now to them.