Kor Meteor is a young man living in a small village by the sea and training in the ways of the sword under his grandfather's tutelage, who bequeaths to him an unusual weapon known as a Soma, which can harness the power of a person's Spiria--the embodiment of their heart and soul. Kor encounters a travelling pair of siblings, Kohaku and her brother Hisui. However, in an unexpected turn of events, Kor accidentally shatters Kohaku's Spiria Core, the source of her emotions. Now, the trio must embark on a journey to make Kohaku's heart whole once more.