Ningyou PassNingyou Touge; 人形峠; Ningyou Pass

A group of high school students visit the inside of a mountain on an agricultural trip. While staying at a farmer's home, they learn the rural life. However, the village doesn't exist? A shudder runs down everyone's spine as a lot of inexplicable events happen in the village, that now restricts entry. What are the high schoolers' fate?