With her school shutting down, Tamaki Minase fears that she will never see her boyfriend, Yuuma Shindou, again, as he will soon be moving to another town. So when she comes across a charm called "Sachiko-san Ever After," which will supposedly bind people together forever, Tamaki begs Yuuma to do the spell with her. Just as the two are about to perform it, the school bully Erina Yuzuki and several other classmates decide to ruin the couple's alone time and participate in the ritual.

However, after the spell is complete, the group is transported to an old school that shut down 30 years ago: Tenjin Elementary School. Separated on arrival, they wander the halls trying to find each other, coming across the bloody remains of victims that had previously been drawn into the school. Soon, they are hunted by the evil that lurks within the cursed building, and they must find a way out or become corpses themselves.