Sugomori City is an imaginary Japanese city built on reclaimed land. The city’s population decreases as years goes by. One fine day, Sonosaki informs her schoolmate Katsuhira that she has been chosen to be a Kiznaiver. Kiznaiver are connected to the Kizuna System, an incomplete system implemented for world peace to share injuries among other Kiznaivers. It also allows them to connect with their partner’s personalities and lives even though they are completely different with theirs.