Kazuki Nishido

Misuzu's former senpai in college and current boyfriend. At 27, he is already principal of the high school she teaches at. Kazuki is Masahiro's older brother, though the two hate each other. Note: in "Sensei no Okiniiri!", Kazuki's last name is translated as "Seidou", while in "Zoku Sensei no Okiniiri!" it's listed as "Nishido".