From the introduction:
Kyoto is in chaos, and soon the Shogunate will crumble as the social order it maintained for so long comes undone. Amid this, you, the samurai of the Shinsengumi, fight a losing battle for the old guard while you scheme for prestige and power. Recent events have left a gap in leadership of your unit, and anyone who attains captainship has a shot of rising to the innermost circle of the Shinsengumi -- and gaining all the status and wealth implicit in that position. This game is fundamentally one of backstabbing and conflict, of honor and shame, war, peace, and the disintegration of the social order. This is a competitive game -- you must make sure the unit falls into your capable hands, and in doing so must discredit (or assassinate) your rivals, all while carrying out your sacred duty to restore order to the Old Capital.