In the Kingdom of Siegerland's annals, a legendary Shadow Messenger has long safeguarded the realm, an enigmatic figure devoid of a shadow. Each Messenger selects a knight to pledge allegiance by offering their own shadow, transforming them into a revered Swordsman. Lisa, living a content life, faces a tragic loss when her father passes away, leading her mother to confine her indoors. Unyielding, Lisa sneaks out with her friend Louis, only to witness a chilling incident where her companions perish mysteriously. As the sole survivor, she grapples with amnesia shrouding that fateful day.