Return from time to time: suddenly it's a different world
Another?
There may be many extras..., Because I haven't thought about the main plot yet, so I will write the extras.
2023.3.20.00.07: In terms of extras, they are things in the past, present and future, which may or may not be related to the main plot. Because it cannot be well connected with the current main line, it is called a side story.
Intention: If you don't experience it, you won't know it.