In an Edo-era Japan lush with a variety of sword-fighting styles, Shichika Yasuri practices the most unique one: Kyotouryuu, a technique in which the user's own body is wielded as a blade. The enigmatic seventh head of the Kyotouryuu school, Shichika lives quietly in exile with his sister Nanami until one day—the wildly ambitious strategist Togame barges into their lives. Togame brazenly requests that Shichika help in her mission to collect twelve unique swords, known as the Deviant Blades, for the shogunate. Shichika accepts, interested in the girl herself rather than petty politics, and thus sets out on a journey. Standing in their way are the fierce wielders of these legendary weapons as well as other power-hungry entities who seek to thwart Togame's objective. In order to prevail against their enemies, the duo must become an unbreakable team as they forge ahead on a path of uncertainty and peril.

On the surface, Ryousuke Kaga is the token perverted teenager, spending his days ogling women and indulging in erotic reveries. Because of this, Ryousuke is ostracized by his classmates. Only his childhood friend Mina Okura knows that behind his lecherous persona lies a compassionate boy who has sworn to be chivalrous to girls, believing they are treasures that must be protected. One fateful day, Ryousuke runs into Lisara Restall, a Soul Reaper hailing from a noble family, whose primary objective in the human realm is to locate a magically potent person known as the One. In order to fuel her movement with magic, she decides to form a provisional contract with Ryousuke: to use his sexual desires as a source of energy. Carrying out this peculiar arrangement with Lisara, Ryousuke encounters many disparate individuals but also learns of the intriguing yet dark secrets surrounding his world.

After surviving the brutal challenges of Idofront, Riko now possesses a White Whistle, allowing her to descend into the Abyss's sixth layer—The Capital of the Unreturned. Alongside Reg and Nanachi, Riko begins to explore the uncharted domain, where the ruins of the promised Golden City are located. As the trio starts to adapt to the harsh environment, they soon encounter dangerous creatures and treacherous landscapes. Their expedition leads them to a village inhabited by strange beings known as hollows. Despite the creeping sense of unease that welcomes them, the three venture onward to uncover the mysteries of the settlement and long-lost legacies of the forgotten adventurers who once descended into the horrors of the unexplored Abyss.

Hidden in plain sight, spirits known as youkai inhabit the world. While most are benign, a certain subset threatens the tenuous peace between youkai and humanity. Ever since she agreed to become their God of Wisdom, Kotoko Iwanaga has served as a mediator between the two realms, resolving any supernatural problems that come her way. At a local hospital, Kotoko approaches Kurou Sakuragawa, a university student whose long-term relationship ended with an unfortunate breakup. Kotoko harbors feelings for him and suspects that something supernatural lurks within his harmless appearance, so she asks Kurou for his assistance in helping out youkai. Two years later, news of an idol who was accidentally crushed to death by steel beams flooded the press. However, months later, sightings begin to tell of a faceless woman who wields a steel beam. As is the case for any supernatural problem, Kotoko and her partner set out to stop this spirit from wreaking havoc—but this case may prove to be far more sinister and personal than they could have ever thought.