Majiru Itoshiki  

Break off-chan, 糸色交

Enishi's nephew, who was sent to live with Nozomu after his parents abandoned him, is a young man named Zekkō. Despite being rather arrogant for his age, he has experienced psychological trauma due to the actions of Nozomu's students. His name translates to "breach in a relationship," which hints at the complex emotions and relationships that exist within this story. It is suggested that Zekkō harbors feelings for Kiri Komori, one of Nozomu's students, but refers to her as his big sister instead.