Seonbae, Igeo Yeongu Majayo?

In a society where shapeshifters and humans coexist, Kim Ga-Il faces even more prejudice and hatred as a fox shapeshifter. After falling for a gangster he spent a night with while drunk, Ga-Il discovers that he is actually Kang Shin, a model student and senior in the Shapeshifter Research Department. Fascinated by this cool yet sexy senior, Ga-Il eventually decides to become the subject of Shin's research...

(Source: Bomtoon, translated)