When the students enter the game, they hide between their uniforms and the uniforms of the other students. They can't find the person who sent them the package, because the uniforms are all made by the students at the school, and they don't know anyone else who did the same thing. The only person who knows the person behind the wolf is the volunteer who helped prepare the uniforms for the students this year. He's able to figure out the person's identity by looking at the marks on the wolf's uniforms. The other students are shocked to find out that the students are all students, and that the wolf was invited by the school. They're even more shocked to learn that the wolves are students, since they're all wearing the same uniforms.