Gehenna: Where Death Lives by Hiroshi Katagiri

5.10

A group visits Saipan to search for locations for their company's newest resort. As they find what they think is the perfect spot, they discover a hidden bunker on the property which they decide to explore. However, they soon find out that curiosity can kill. As each member faces their most private secrets and the secrets of the bunker itself, the results lead to a most shocking conclusion.