22 years ago, a huge alien artifact is found on a construction site by a worker named Yotsuga. The foreman orders that the artifact be broken apart so as to avoid delays. As Yotsuga walks towards the dumpsters to dispose of a small piece of the artifact, the world splits into two; in one world, Yotsuga tosses away the piece and the artifact is destroyed; in the other, Yotsuga keeps the artifact, leading to the discovery of extraterrestrial technology that changes history.