Unfortunately, not all content for Shogun 2 was made available on Steam. Historical Battle of Kawagoe was added to the pre-order version of Shogun 2 in GameStop shop in January 2011. It is not available for all players community for this day. If you do not have any plans to add this battle as Dlc , maybe you can release this a free patch? I would be very gratefull.https://forums.totalwar.com/discussion/5694/preorder-bonus-informationhttps://www.reddit.com/r/totalwar/comments/7qbuaj/the_lost_dlc_battle_of_kawagoe/https://www.youtube.com/watch?time_continue=1&v=zw0SOaenaFo&feature=emb_logohttps://steamdb.info/app/34346/
I know that is a mod which unlock this battle in custom battles but we don't have possibility to chanege battle dificulty and not everyone play the game with mods.