Click to enter the game, and the invitation order of the ruins library is invited according to the rank order of the characters.

The premise of all ordinary invitations to war has nothing to do with the main line. As long as you see that the invitation on the right is red, it means it is related to the main line. There may be a battle that needs to be played behind the main line to unlock it. In this case, the book delivery will prompt "There are no guests to receive at present".