9-nine-:Episode 4 by Palette - Adult Sex Game

Overview:
Shiromitsugawa City: an academic city with no other particular features.

A large earthquake hits the city, damaging the sacred treasure in the Hakuda Tsukumo Shrine, and causing strange items to appear from a parallel world. These "artifacts" grant strange powers to their owners, with incidents of an owner abusing their powers and turning people into stone.

Having learned of the item that causes this petrification, the "Evil Eye Artifact", Kakeru Niimi teams up with his classmate, Miyako Kujou, and his sister, Sora Niimi, to investigate and put a stop to the culprit.

During the investigation, they find themselves at odds with "Rig Veda", an organization of artifact users. Among their members, they spot their upperclassman in school, Haruka Kosaka.

9-nine-: Episode 3 is the latest chapter in this series of supernatural mystery visual novels with the focus now shifted towards a new heroine, Haruka Kosaka.​