The Ninja World Inside a Box

This is a little box measuring one meter on each side.

It may look small, but there's a whole world inside:

It has towering mountains and mighty rivers, bright days and a shining moon, an endless sky and a vast ocean, goddesses and immortals.

It even has a bunch of little people who call themselves ninjas and can spray water and breathe fire, fighting with blades and weapons inside.

"Mm, this is the world I created."

"Looks pretty good, doesn't it?"

"Wait, why can these little people reverse life and death? They can even rewind the timeline?"

"Damn it, there's another BUG in this world!!!"

This novel and its characters are entirely fictional. Any resemblance to real people or events is purely coincidental. Do not imitate.