Concave and Convex World Short Story Fanfic: Origin

I am a former veteran of the Seventh Creation Society. Although I have left, my passion for the concave and convex world has not faded. This article is a short fan story created in the early years. It mainly includes some of the past experiences of some of the main characters in the original work. It can be viewed as a prequel. The characters in the animated feature recall the plot, and some of them refer to these fan articles of mine, although there is no signature of mine on the script. , But I am still very happy to contribute to the work I love. Since this article is the concave and convex of my personal perspective, as a fanfic, it may be different from the general audience's perception. Let me say hello in advance, it may be OOC, or it may not be. If you like it, I am very happy. If you don't like it, please feel free to comment. Thank you.