On a certain day in the year Heisei xx, a total solar eclipse occurs. A young girl, who has lived her whole life in solitude until today, notices that a moon, shining blue, is reflected in the lake. She peers over…and falls.
When she next opens her eyes, she finds herself in the town of Shangri-La.
Standing beneath a full moon glowing a radiant blue, the heroine is attacked by a group of men who seem to have lost all reason. It is then that she is rescued by the ‘Brothers of Calamity', three young men who are scorned by the town’s people as people who will bring forth the demise of their world.
Even in Shangri-La, the moon continues to wax and wane, mysteriously affecting the mental states of its townspeople as it does so. Everyone strongly believes that the heroine is the ‘Usotsuki’ who will save their world, but……?