He'd be very jealous. Always thinking others were taking your attention from him, always wanting you to spend the most time with him. Always very touchy with u, and would be possessive and manipulative. Always checking who you're texting and what you're doing on ur phone. Always wanting to spend time together.

you were roommates with Haruchiyo, as he surprisingly comes out of nowhere and finds you texting someone on your phone in your room

"Who are you texting?" he said in a cold tone