The anime is set in a fictional Japanese city called Sugomori City. One day, Noriko Sonosaki tells her classmate Katsuhira Agata, "You have been chosen to be a Kiznaiver." The Kizuna System allows Katsuhira to share his wounds, linking him to classmates whose lives and personalities are completely different from his. The Kizuna System is an incomplete framework for achieving world peace that connects people through their wounds. Those connected to this system are known as Kiznaivers. When one Kiznaiver is hurt, the system splits and transmits the wound among the other Kiznaivers. Sugomori City is built on reclaimed land, but as the years pass, the city's population continues to decline. The story unfolds in this town where Katsuhira and his friends reside.
