剣と魔法が支配する遠い時代のことである。ある時、魔竜族に、ドラゴンにまたがった竜騎士が敢然と立ち向かい、民衆を鼓舞したという。悠久に続くと思われた戦いの末、魔竜族の首領である三魔人を封印した。そして、十数年の歳月が流れた……。 In a fantasy world, a young would be dragon knight sets out to find his own dragon mount. In a bloody incident, he finds that mount and more with Karin, a beautiful girl who reveals she is a dragon demon whose various forms includes a dragon one that is excellent for Rike's riding needs. The pair hit it off well and become lovers, but that brings its own problems when Rike's other girlfriend, Lydia, learns this development. In a fit of jealousy, Lydia calls upon demonic forces to respond, but that choice brings disaster. The arrived demons seize control of the lady and plot their own revenge that will take all of the young knight and partner's power and love to stop.