Background With Other Anime Characters

Having in mind that the game will not have so many anime characters because of its size limit, I thought it would be interesting if the game had backgrounds with other animes that have no characters in the game, just to tribute them and expand the diversity of animes in the game.
For Example: Probably There won't be any Trigun characters on this game, so the staff could create a background from Trigun and include there Trigun characters like Wolfwood, Knives and even Vash!