Gate World, Visitors from Outside the World

"Fantasy infinite flow + growth + passion + alien confrontation" This is a world of "doors". Everyone can try to open a door of their own before the age of 15. There is a "state" inside the door, and every time you break through, the state will undergo earth-shaking changes. In this world, there is a special kind of door, and the people who summon this kind of door are called "door craftsmen". The most special thing about them is that they can "repair doors."