This is a fanfic of the concave and convex world, with Reka as the main CP, and there are many follow-up CPs. After writing this book, there will be an ancient fanfic of the concave and convex world.
Concept: Leian, kid, don't disturb me. I only wrote it because the author really likes the episode 1 of Reka CP in the concave and convex world.