Kiichiro, a high school student haunted by a near-death experience, finds himself bound to Tanmoku, a spirit from the underworld who saved his life. Their contract is simple: Kiichiro must help Tanmoku resolve unfinished business among the living, and in return, the spirit keeps him alive. What begins as an awkward partnership transforms into something deeper as the two navigate a shadow world lurking just beneath everyday reality. Supernatural cases pile up quickly. Vengeful spirits, cursed objects, and entities trapped between worlds all demand attention. Kiichiro discovers he can perceive what others cannot, making him uniquely suited for this work despite his initial reluctance. The bond between him and Tanmoku grows tested by each new encounter, forcing both to confront what they're willing to sacrifice for one another. Comedy threads through the darkness as the pair's mismatched dynamic creates constant friction and unexpected moments of levity. Beneath the humor and action pulses a genuine question: what does it mean to be bound to someone forever, and can that binding evolve into something chosen rather than forced?