Majiru Itoshiki

Nozomu's nephew, the son of Enishi. He was sent to live with Nozomu when his parents abandoned him. Although he is rather arrogant for his age, he is quite vulnerable to the psychological trauma caused by Nozomu's students. His name becomes zekkō (絶交?, "breach in a relationship") when compressed. It is hinted he has feelings for Nozomu's student Kiri Komori but so seems to hide this and refer to her as big sister.

(Wikipedia)