The unwitting founder of the eponymous Katsuyoshi Shogunate in Imperium Offtopicum 23. Originally an unassuming accountant named Naoki Eguchi, he was swept up into the resistance movement against Terminator-style rogue A.I. that forms part of the game's backstory. Shrewd tactics and personal bravery won him the rank of lieutenant colonel in the "National Resistance Army", a loose confederation of volunteers, desperadoes, and conscripts supplementing the decapitated JSDF. However, after the war the NRA collapsed into regional warlords; the death of Eguchi's superiors in a rival raid left him in command of one such warband whose allegiance he secured in a reprisal campaign. Realizing the infighting would bleed what was left of Japan dry, he led his troop in a "March to Tokyo", recruiting whomever he could and slaughtering the warlords that refused. Reaffirming allegiance to the Emperor, he worked in concert with other Tokyo-aligned factions and the surviving JSDF to pacify the country through a combination of diplomatic carrots and military sticks.

Following the reunification of central Honshu, Eguchi was named Supreme Commander de jure, and by the end of the Second Sengoku was effectively elevated into dictator of Japan by a grassroots personality cult spearheaded by the army. He was actually averse to leading the government, assuming his position as Shogun would default to a ceremonial title, but was persuaded to stay on based on his popular image and personal administrative skill, especially valuable to logistical reconstruction; essentially forced into permanent celebrity, he adopted the surname Katsuyoshi in acknowledgment of his prestige. He did, however, seek to prevent the quasi-feudal postwar order from consolidating into a throwback warrior caste, keeping regional commanders in regular rotation to weed out corruption and patrimonialism. Ironically, by the end of his life he was forced to accept that the shogunate had solidified into a bona fide dynastic position, and trained his son for both political and military leadership in the hope of carrying forth national recovery under a competent government.

• I don't recall the original sources for his name: rendered in in traditional Japanese, 江口 直輝 (Eguchi Naoki) translates as "river mouth prodigy"; an alternative version, 栄口 (Eiguchi) translates as "prosperous entrance". His adopted name Katsuyoshi (勝義) translates literally as "righteous victory"; it is conventionally a male given name, not a surname.

Satoshi Katsuyoshi
Son and heir, serving as Shogun during the game's term.