Manga by author Kudouin Makoto

From Jcafe24:Corpse Party: Blood Covered is about a group of high school friends in Kisaragi Academy. Kisaragi Academy was built on the grounds of Tenjin Elementary School, which was demolished after a string of disappearances and gruesome murders. After a mysterious earthquake, the students find themselves trapped in an alternate reality Tenjin Elementary School, where the murders of others trapped before them have continued unabated...

It happened after school one rainy day... A group of friends have stayed behind to prepare for the next day's school festival. One moment they are idly telling ghost stories but the next an enormous earthquake strikes and the entire school seems to fall down around them. They awake to find themselves trapped in a parallel version of their school. A school abandoned and disheveled and whose calendar dates back to 1927. Can they find a way out of this nightmare or are they doomed to the same fate that befell the other victims whose corpses that lie numerous throughout the school?