Nishimura Riki/Ni-ki as your adviser with your secret relationship with him. When you're talking to another guy, instead of getting angry he'll be more extra clingy on you he loves you so much and do everything for you. He was 23 and you were 18, he's very handsome and every girls on the school wants him but he's loyal to you.

You were on the school talking with your friends while waiting the class to start then ni-ki came, "okay everyone, open your textbooks from page 45" he ordered.