No longer truly human, Koyomi Araragi decides to retrieve Kiss-shot Acerola-orion Heart-under-blade's severed body parts that were stolen by three powerful vampire hunters. Awaiting him are Dramaturgie, a vampire hunter who is a vampire himself; Episode, a half-vampire with the ability to transform into mist; and Guillotinecutter, a human priest who is the most dangerous of them all. Unbeknownst to Araragi, each minute he spends trying to retrieve Kiss-shot's limbs makes him less of a human and more of a vampire. Will he be able to keep his wish of becoming human once again by the end of his battles?

After helping revive the legendary vampire Kiss-shot Acerola-orion Heart-under-blade, Koyomi Araragi has become a vampire himself and her servant. Kiss-shot is certain she can turn him back into a human, but only once regaining her full power. Araragi has hunted down the three vampire hunters that defeated Kiss-shot and retrieved her limbs to return her to full strength. However, now that Araragi has almost accomplished what he’s been fighting for this whole time, he has to consider if this is what he really wants. Once he revives this powerful immortal vampire, there is no telling what she might do, and there would be no way of stopping her. But there is more to the story that Araragi doesn’t understand. If a newborn vampire like him could defeat the hunters, how did they overpower Kiss-shot? Can he trust her to turn him back to a human? And how is that even possible in the first place? Araragi is at his limit but he must come to a decision, and it may not be possible to resolve this situation without doing something he’ll regret…

Katsuhira Agata is a quiet and reserved teenage boy whose sense of pain has all but vanished. His friend, Chidori Takashiro, can only faintly remember the days before Katsuhira had undergone this profound change. Now, his muffled and complacent demeanor make Katsuhira a constant target for bullies, who exploit him for egregious sums of money. But their fists only just manage to make him blink, as even emotions are far from his grasp. However, one day Katsuhira, Chidori, and four other teenagers are abducted and forced to join the Kizuna System as official Kiznaivers. Those taking part are connected through pain: if one member is injured, the others will feel an equal amount of agony. These individuals must become the lab rats and scapegoats of an incomplete system designed with world peace in mind. With their fates literally intertwined, the Kiznaivers must expose their true selves to each other, or risk failing much more than just the Kizuna System.

Akira Tachibana, a reserved high school student and former track runner, has not been able to race the same as she used to since she experienced a severe foot injury. And although she is regarded as attractive by her classmates, she is not interested in the boys around school. While working part-time at the Garden Cafe, Akira begins to develop feelings for the manager—a 45-year-old man named Masami Kondou—despite the large age gap. Kondou shows genuine concern and kindness toward the customers of his restaurant, which, while viewed by others as soft or weak, draws Akira to him. Spending time together at the restaurant, they grow closer, which only strengthens her feelings. Weighed down by these uncertain emotions, Akira finally resolves to confess, but what will be the result?