Tsumugi, often referred to as ‘Mugi’, is a wealthy girl with a gentle and sweet personality. She is the keyboardist for the light music club. She plays the Korg Triton Extreme 76-key keyboard, though she is also seen playing a Korg RK-100 keytar. She intended to join the choir club, but joins the light music club instead. She is considered a piano prodigy since she has been playing since she was four and has experience winning in various piano contests. She has unusually large eyebrows, which apparently run in her family. She is the daughter of a company president, and her family owns several villas in various places around Japan, and one in Finland. She often brings confectionery and assorted sweets and pastries to the club, and makes tea with a tea set which is kept in their club room. Despite her wealth, she is often fascinated by and joy in normal commoner activities, such as ordering fast food. She occasionally displays a rebellious streak.