Corpse-Party: if - Past End

In the original NEC PC-9801 game CORPSE-PARTY by KENIX SOFT, a group of high school students (Satoshi Mochida, Naomi Nakashima, Yoshiki Kishinuma, and Ayumi Shinozaki) from Kisaragi Academy, along with Satoshi's younger sister (Yuka Mochida) were dragged into a cursed schoolhouse. Later, Ayumi, Naomi, and Yuka all fell victim to the girl in red. It was only Satoshi and Yoshiki who managed to escape that nightmare. However, when Satoshi returned home, he was then killed by his dead sister's spirit. In the end, the only one who survived was Yoshiki. CORPSE-PARTY if PAST END's story begins 8 years after that event...