人間シリーズ•

Ningen Series

Spinning off from his Zaregoto series, these novels feature the Zerozaki family, the only one of the seven killing families not to be actually related to each other. Zerozakis spontaneously emerge every so often from the general populace, and define their family connections by which fully fledge Zerozaki discovers and trains them. (Source: easternstandard.pbworks)