This article is a science fiction novel with two male protagonists. It contains three worlds, the human world, the "different time and space" and the ghost world. In different time and space, everyone has a number, and the smaller the number, the more powerful. A strong man with the number 004 once met a human boy by accident, and appeared in various ways during his childhood. However, in the end, his memory was deleted, and other things replaced 004's company. The subsequent encounters were no longer a coincidence, but a deliberate appearance due to longing.
Concept: Encounter across time and space