This is the story of the unscrupulous director of the Space and Time Bureau who lets a certain sparrow go on an adventure.
What changes will happen when 18 comes to the world of 6927? It's an unscrupulous interest.
Here is the formal introduction:
——We are not from the same world, and there is no intersection.
——But now we can no longer return to the state we were in at the beginning, so that's it