Re/Member

High school student Asuka sees the appearance of a dead student named Haruka and tries to find her body. Asuka and her friends try to find the eight scattered pieces of Haruka's corpse in the school. In doing so, they learn more about the Red Person who is pursuing them. The Red Person hunts down the students who are alone in the school to kill them, and until they exit the school gates, the Red Person will keep appearing before them. When the Red Person kills a student, it scatters the student's body into eight pieces and tasks others to find the pieces in the school. If Asuka does not find Haruka's body, the day will keep repeating and she and her friends will continue to die until they find it. (Source: MyDramaList) ~~ Adapted from the web novel "Karada Sagashi” (カラダ探し) by Welzard (ウェルザード).