It's been 20 years since a meteorite known as "Black Night Siderite" landed on Earth and the world fended off an attack from the beings now manifested known as "D2s". Music has been banned since then as it seems to attract them. One day while the talented pianist Takt finally dec...

Lady Ameth predicted the Princess Knight named "Yuuki (Japanese for courage)" would appear one day with amnesia. Kokkoro is sent to find, protect and guide him but unfortunately, her funds weren't enough to get them by at the capital of Landosol. As they go questing to earn more...