Shuuchaku to Inu

Midori, who has a past of being humiliated as a “dog” by his classmates, has been living a peaceful university life far away from his hometown. But after a year passes since his enrollment, everything changes when a handsome new student named Sugihara joins the same club as him.

“I am not threatening you, I'm loving you.”

(Source: Frontier Works, translated)

Note: Includes one extra chapter.