You are walking around the forest in your town, when you see a massive crater. You see a white gazebo-looking thing in the middle of it. When you get closer, you realize it's actually a spire. You walk inside it, but the floor breaks and you fall down. You soon wake up after being unconscious in a dimly lit room. You hear voices outside the door.

Sanzu: "How did they get here?" Rindou: "Probably the same way we did, stupid." Ran: "They're pretty~" Kokonoi: "That's what you're thinking about?"