Hiroto Domori was born into the Domori family, a lineage of the strongest spirit swordsmen who inherit extraordinary powers.

However, he inherited both spiritual and magical powers from his parents—two opposing forces. This resulted in a peculiar condition: if only his magical power was sealed, his spiritual power would simply leak out, leaving him unable to wield either. Consequently, he was unable to inherit the family's powers.

Therefore, he received training in immortal arts from Son'i, the grandchild of his grandfather Tenzo's acquaintance.

Hiroto displayed an exceptional aptitude for mastering these immortal arts. During his training, he discovered a unique property: his immortal qi did not conflict with either spiritual or magical power. This allowed him to wield an unparalleled force—the simultaneous use of both spiritual and magical powers. However, this power came with a grave price...

Upon entering high school, his ultra-free-spirited grandfather, Tenzo, squandered his living expenses. Citing financial hardship as an absurd excuse, Tenzo then kicked Hiroto out of their home. Hiroto enrolled in Houraiin Kirin High School, which generously allowed him to defer his tuition payment until he achieved success.

There, he started his high school life with his childhood friend Mari, who had rejected him in the past, and his friends Ichigo and Shizuka. However, due to various misfortunes, his household finances were in dire straits.

Unable to find a decent part-time job and plagued by persistent financial worries, Hiroto decides to take the rank certification exam for the World Ability Users Organization—a move that is also a taboo for the Domori family—all to secure his livelihood.