After forming a friendship with his classmate Tsubasa Hanekawa, Koyomi Araragi—once a cynical and isolated high‑schooler—begins to see life in brighter terms. One evening, while making his way home, he comes across a spectral woman whose limbs are severed and who clings to life. Though hesitant at first, Koyomi eventually consents to exchange his own existence for hers and allows her to drink his blood.
When he awakens in a derelict building, he is shocked to discover that the vampire he rescued, Kiss‑Shot Acerola‑Orion Heart‑Under‑Blade, has rendered him almost immortal. Fortunately, a path back to mortality exists. With the help of Meme Oshino, a specialist in anomalies, Koyomi must confront the three vampire hunters who stole his new master"s limbs to restore Kiss‑Shot"s full power. Determined to reclaim his former life, he will pursue his aim relentlessly. Yet the greatest test may not be defeating foes but maintaining his own humanity.
