For their upcoming release of Corpse Party The Anthology: Sachiko’s Hysteric Birthday Game of Love 2U for the Playstation Portable, 5pb will be including a bonus anime episode entitled Corpse Party: Missing Footage with its limited edition bundle. Currently the overall plot is unknown for this release however it does touch upon some elements that were briefly shown in Corpse Party: Blood Covered, as well as providing footage from outside the haunted halls of Heavenly Host Elementary School (Which were also occasionally shown in the game). Due to an increase in CERO ratings by this OVA, the limited edition is rated 18+. Both editions will be available for purchase on the 2nd August 2012 in Japan.
The original Playstation Portable release of Corpse Party: Blood Covered Repeated Fear was localized into English last year by the team at XSEED Games and reception has in my opinion been rather strong. However, currently no announcement into the release of Corpse Party The Anthology OR Corpse Party: Book of Shadows has been made by the company as of this post.
The Corpse Party franchise began in 1996 when the first game was developed using RPG Maker software for the PC-9801 and several years later has been released on both the PC and Playstation Portable in a number of forms alongside several manga series.