I'm Just an Ordinary Student, Killing Gods Outside School

Have we ever thought that under the bustling city, there are unknown strange things? Have we ever thought about whether there is a tall door hidden in the corner of the world. Have we ever thought that in modern cities where people come and go, there is a special group of people. We often dream about all kinds of strange events, why do they appear in our dreams. We once longed for the existence of a parallel world, but does it really exist? If a parallel world really exists, will it be what we expect?