As college exams loom, Tohko Amano, the literary club's unconventional president known for her book-devouring habit and expert procrastination, shocks everyone by halting club activities. This sudden change leads Konoha, burdened with dodging his strict supervisor's story requests, to assist his distant classmate Nanase Kotobuki in the music room. However, when Kotobuki's friend mysteriously disappears before Christmas, allegedly embodying the enigmatic 'Angel of Music,' Konoha is drawn into a captivating mystery reminiscent of Gaston Leroux's renowned tale.