Osprey has a solid list of reading material. Won't knock your socks off, but it's a good starting point:

https://ospreypublishing.com/catalog...amurai+history

"A History of Japan" By George Sansom, vol II is a huge, in-depth read. Vol I covers Japan pre-1334; Vol II from 1334-1615; Vol III from 1615-1867. If you have Kurosawa's movies----watch them.