@BlazeSaber is partially right. It is true that you can't update the existing app, if the new apk doesn't allow it. But you can go to your files on your phone copy/take the save files, put them somewhere you will find them, delete the old version, install the new version and place the files in the folder.
Path: 0/ android/ data / homecoming.morenatsu.revisited/ files/ saves... And there you have it. :)
(I use ES Data Explorer, may need pro version. Or use Total Commander. Just try a few file managers and see which one works best for you)