The Tale of Zatoichi Noir

The era is the Tenpo era, set in the Edo period, on the eve of the end of the Tokugawa shogunate. In a world where common people suffer from high prices, rice shortages, political corruption, and epidemics, a lost swordsman and his Akita dog embark on a journey in pursuit of "righteousness" and "strength." Where do they come from, and where are they headed? Will they find light or darkness at the end?