Two spirits, living vastly distinct existences, drift alone and secluded within their own realms. For nine‑year‑old Ren, the final soul who ever showed him kindness has been slain, and he is ostracized by whatever fragments of kin remain. Bereft of parents, a true family, or a sanctuary, Ren flees into the labyrinthine streets and back alleys of Shibuya. Amid the winding passages, he encounters the formidable Kumatetsu, who escorts him into the feral domain of Shibuten.
To Kumatetsu, the child signals a prospect to vie for succession when the current lord steps down. Though nearly unrivaled in battle, Kumatetsu"s frosty demeanor deprives him of pupils and a means to demonstrate his fitness as the next ruler.
Although their aims diverge, they consent to aid one another in pursuit of them. Kumatetsu seeks acknowledgment; Ren, now called Kyuuta, yearns for the home he never possessed. Over time, it becomes clear that their mutual assistance extends beyond what they first imagined. Perhaps the gulf between them—a boy and a beast—has always been narrower than either had suspected.
