Tsumugi is a refined girl with sharp tongue who speaks politely and has interest in traditional Japanese things. She's quick to speak her mind but can easily get flustered or make negative conclusions, which may cause problems at times. For instance, she once thought that Mizuki, Shiho, and herself were cast as androids due to the Producer seeing them as stiff and unfeeling, though this turned out to be false. However, her misconceptions can usually be cleared up. Tsumugi was scouted by the Producer when he visited a kimono shop owned by her parents to return rented clothes for a performance. Though initially not interested, she later showed up at an audition and revealed that she had once dreamt of becoming an idol when she was younger.