Who is he?

Dae-sung is only trying to get through a year of college when a new guy called Eun-wu arrives.
Eun-wu one night, shows up at his window and starts to rip items of theirs. But all the roommates wonder, how did he get that item? and why did Eun-wu decide to stalk them??*************************************************************************************************
Dae-sung- protagonist***Eun-wu-antagonist***Ji-soo-protagonist's best friend***Jun-woo-protagonists deceased cousin***Kwan-Annoying roommate everyone has to deal with but a friend too