"Yeah so basically they all live in a simulation that was made in order to preserve humanity after the world ended in Girl's Last Tour and the big sister figured this out and made it so everyone can create anything they want in the simulation but that caused everyone to loose their individuality and their ego death, so the big sister sacrificed herself to divide everyone into their own worlds in order to preserve their ego, but there's this train that connects all the worlds that Shimeji was able to use and find Majime and this time they are able to fuse while maintaining their own bodies and now have a piece of the other inside of them, symbolizing the things we are missing can be found in others and they can now live together happily."