Following her father's death, Ren Taki journeys to Vienna to honor a promise she made to him: to attend the Melite Conservatory of Music. During her travels, she encounters the flirtatious musical prodigy Wolfgang Amadeus Mozart, who is taken aback by her intention to enroll at Melite. It turns out that Melite is an all-boys institution! After speaking with the headmaster, Ren gains admission as a student under the male pseudonym "Rentarou." Bound by secrecy, Mozart is assigned as her roommate. In this new environment, Ren encounters eccentric classmates such as Johann Sebastian Bach and Pyotr Ilyich Tchaikovsky; however, since they reside in the same dormitory, keeping her secret from them proves to be a difficult and endless task. With Mozart's assistance, she conceals her gender while striving to remain at the prestigious school. Surrounded by peers of extraordinary talent, Ren works hard to match their abilities and compose resonant musical pieces.