For the Shōgun's Head, that's the title I originally came up with, mainly because titles like Sengoku, Gekokujō, and Tenka have already been taken.
Originally, Shōgun's Head was going to be a boardgame that I had prototyped back in 2014. The concept was for players to be daimyō fighting for control over the provinces of Japan. Besides the economic strategy, there were elements of clans and named samurai, raising families of samurai to bolster one's armies and marry into other clans. Opponent players could be vassalised by either conquest on the battlefield or by strategic marriages and alliances. Time was also an element for samurai to grow old and die.
Of course, the limitations of a tabletop boardgame meant there had to be a limit on the elements to reduce the clutter of pieces and condense into a playable timeframe.
Later I discovered roleplaying, and in the summer of 2022 I decided to create my own samurai roleplay. I had looked at various existing roleplay systems, such as Legend of the Five Rings (L5R). But many of those proved to either have very narrow scope or, like L5R, do what today would be called cultural appropriation. Though written by the same designer as L5R, I found Blood & Honor (B&H) to be the closest to what I was looking for, with some tweaking.
Using the power of Kanka, many of the elements from the boardgame I have combined with B&H rules. And here it is.
Films that I also use as inspiration: 時代劇映画 Samurai Films