some scenes are in the game nothing really special imo (the OVA only last up to 11 mins+)

and it seems there will another OVA called "Corpse Party: Tortured Soul." probably gonna be bundled again with the new Corpse Party installment called "Corpse Party: Blood Drive" release date is still unknown (sequel of Corpse Party: Book of Shadows)



EDIT: Corpse Party: Missing Footage came with the game called "Corpse Party - THE ANTHOLOGY- Sachiko's Game of Love - Hysteric Birthday 2U" is a romance-comedy spinoff of the original games created by 5pb. And it takes place on Sachiko's birthday.