A manga based on Japanese historical figures is almost always difficult to understand. Mangakas usually jump right into the story because the assumption is you already know who the important historical characters are and what happened. Its like if you write/draw a manga about George Washington...we already know he kicked some English butt and became president. Its a good idea to google it just to get some historical context - that way you learn some japanese history and the story makes more sense. The translator sometimes will write technical notes so you understand whats going on but that doesn't always happen.
A manga based on Japanese historical figures is almost always difficult to understand. Mangakas usually jump right into the story because the assumption is you already know who the important historical characters are and what happened. Its like if you write/draw a manga about George Washington...we already know he kicked some English butt and became president. Its a good idea to google it just to get some historical context - that way you learn some japanese history and the story makes more sense. The translator sometimes will write technical notes so you understand whats going on but that doesn't always happen.