Onimasa is the egocentric boss of a small yakuza clan on Shikoku Island, whose criminal duties conflict with his self-image as a chivalrous samurai. His struggles with his boss, the Shikoku Godfather, and the tumultuous life of his adopted daughter, Matsue, form the backdrop of this epic tale of justice, obedience, and bloody vengeance.

板仓亮子（宫本信子 饰）是港町税务署的调查员，她工作认真负责，但在收到一位老婆婆的指责后，她不再将目光停留在普通老百姓身上，而是转移到大的商会上面。在她锲而不舍的追查下，许多狡猾的公司老板纷纷现出原形。不过亮子也有为难的时候，经营旅馆业的权藤英树（山崎努 饰）就是一条狡猾的老狐狸，任凭亮子怎样调查也找不到蛛丝马迹。
不久后，亮子因工作出色被调到国税局侦查科，她和同事齐心协力侦破不少偷税案件。随着一同匿名举报电话的到来，权藤的案子再次提出，亮子决心将其偷税事实彻底查清……