An intense suspense about a piano prodigy and her mother's murder by the industry's hottest talent, Hino Hiroko! A country town in Hokkaido. Ritsu is a junior high school student who lives in a house with a piano teacher, and Saya is a transfer student who attends the school. As the two grow closer through a piano competition, Saya tells Ritsu that she wants to kill her mother. Time passes, and ten years later. Ritsu is spending her busy days in the editorial department of a weekly magazine in Tokyo, when a body is found in her hometown in Hokkaido, causing a commotion. A memory of ten years ago and a ten year gap. As if ignoring the length of time, the story now begins to move forward.