Kazushi Tatsuishi

Kazushi Tatsuishi is the eldest son of the Tatsuishi family and the older brother of Kouji, Miyo's childhood friend. He has a carefree demeanor like a playboy, making him a hard-to-read character. Although his father, Minoru Tatsuishi, had planned for him to marry Miyo, Kazushi himself was not pleased with his father's scheme. In the first volume, he supported Kouji's decision to rescue Miyo.

After his father's downfall due to the revealed conspiracy involving Miyo, Kazushi smoothly took over as the head of the Tatsuishi family. To avoid the family's dissolution, he brought the Tatsuishi family under the Kudou family's command. From the second volume onwards, he frequently appears as an ally of Kiyoka, maintaining his carefree attitude while assisting in missions to exterminate aberrations and getting involved in troubles surrounding Kiyoka.