My Friend's Yandere {REWRITING}

Carlo, Ashley, Garlian and Chris are best friends in Class E. The thing is, their class contains a Yandere. They go in a search for the Yandere who killed Yuno and Nagisa. But little did they know that one of them is the Yandere's Senpai. They also didn't know that there is a surprise to come to them. Something they didn't expect.