It's a story about a former Japanese person secretly maneuvering in a different world that has accumulated history in the same way as Earth.
Concealing himself from they eyes of people, he has no interest in things like honour and wealth at all and only moves for the sake of his goals. Before long he starts to influence the movements of the world from the shadows.
The protagonist will change.
Based on the Annals of the Three Kingdoms, it's aimed at those being curious about military history and those, who don't know the Annals of the Three Kingdoms, enjoying to read about it.