There is actually a really wonderful audio book on the history of Japan. It is by the Great Courses series. The audio book contains a series of 24 lectures by a professor of the subject. I got it through Audible. I can vouch for its quality. I have several of the Great Courses...one on Rome, another on Vikings, they are really well done and might be a start for you!
“Hither came Conan, the Cimmerian, black-haired, sullen-eyed, sword in hand, a thief, a reaver, a slayer, with gigantic melancholies and gigantic mirth, to tread the jeweled thrones of the Earth under his sandaled feet.” -Conan, by R.E. Howard