The world is not simply single, there is a boundary within the world - within the boundary
The story is about a group of people who live within the world and occasionally wander outside.
Various desires outside the world will condense into different "thoughts", which are weapons for people inside the world. Different weapons, combined with different mental powers, will produce different results.
Outsiders are ordinary human beings, while insiders have zodiac signs that are similar to the zodiac signs but very similar to the zodiac signs - according to the 12 months, they correspond to the twelve zodiac signs.