Masahiro is the grandson of the famed onmyōji, Abe no Seimei, but he has lost the sixth sense that allows an onmyōji to perceive supernatural beings. With that crucial ability gone, he feels compelled to pursue an alternate career. One day, a mysterious mononoke appears, he names it Mokkun, who, after battling a demon, reveals Masahiro’s true potential powers. With Mokkun’s assistance, Masahiro embarks on a quest to become the greatest onmyōji.