Koi wo Shita Sora no Majika

As a homeroom teacher, Yahaba was worried about Yumino, his beautiful student who couldn’t make friends. When he visited his dorm and tried to help with his problem, he felt that he could no longer stop.
“I can’t say it now, but I won’t let anyone have you.”

A love story between a popular teacher who was trying his best to conceal his feelings, and a determined, tsundere student.

(Source: Renta! JP)

Note: Chapter count includes two extras.