Sky HawkPaperback, 1 October 2019

Two defeated samurai are exiled from Japan during the Boshin War of 1868 as the new Meiji government took hold. Ending up in Crow Territory in North America, they encounter Crazy Horse, chief of the Oglalas, and soon form a profound friendship and respect for each other's cultures. This respect was felt so deeply that the two Japanese travelers end up fighting alongside the Oglalas at the infamous encounter at Little Bighorn.