Shinen naru Renai Tetsugaku: Do-S Kyouju ga Watashi wo Dekiai Suru Riyuu

Tomomi, a graduate student in the Department of Philosophy, has a crush on Professor Takatsuki, who is famous for being a sadistic teacher. After a drinking party, Takatsuki saved her from being taken away by a male student. Tomomi thought, "The professor is being so nice. It must be just a dream," even when Takatsuki leaned down and kissed her. When she woke up the next morning, she found herself in Takatsuki's bed. It wasn't just a dream! As Tomomi panicked, Takatsuki smiled coldly and proposed to her: "Why don't you marry me?"

(Source: Irie Novels, translated)