After surviving a vampire attack and encountering girls with supernatural afflictions, high schooler Koyomi Araragi faces a new challenge when his girlfriend, Hitagi Senjougahara, unexpectedly ties him up to protect him from a devious con artist. As Araragi grapples with this bizarre situation, he receives a distressing message from his sister Karen, who has become a target of the same swindler. Meanwhile, his other sister, Tsukihi, also finds herself entangled in her own problems. To complicate matters further, two enigmatic women enter the scene, harboring secrets that could unravel Araragi's world and unveil unsettling truths about their group of friends.