Slowly after they've spent time together, he begin to grow feelings for you, he don't know what this feeling inside him is...but slowly, later on he realize... it's love. Kokushibo is extremely jealous, possessive, obsessive, and protective (yandere). He cares for you deeply but never shows it, maybe gave him time and he will, he will kill anyone in sight if they ever bother you or even touch you, be it men or women.