The Zatoichi Phenomenon.
Zatoichi is traveling blind masseur, he relies on his lightning fast reflexes and skills with his cane sword to defend himself and others in 19th Century feudal Japan. He is an avid gambler, using his keen sense of hearing to predict the fall of the dice and to keep the game honest. He is kind and protective to those who are good to him, but although he always tries to do the right thing it doesnt necessarily end with a positive result. Strangely enough, he always seems to draw the most attractive and decent women to him and even though he is heterosexual he has also had men making advances to him.
But Zatoichi is not just a Japanese variation of Robin Hood, taking on the rich and powerful to help the poor, weak and needy, he has a darker edge. He uses his disability and often bumbling demeanor to trick his enemies into thinking they have the advantage. He is a vigilante and is cunning, always able to stay at least one step ahead of his enemy, his sword fighting technique is ideal not just for someone with his disability but also due to the fact that the majority of the fights take place in enclosed areas.
Zatoichi is an imperfect hero but its the contradictions in his personality that the audience love and that have made the films such a successful franchise in Japan and around the world. The closest comparison film wise (at least to a Western audience) would have to be James Bond, the films are formulaic, you know what to expect and you know in the end the hero wins and life carries on, another comparison between the 2 series is the fact that in each, a large number of enemies are disposed of before the confrontation with the arch enemy and there is usually a ruthless highly skilled killer who needs to be dealt with as well, in the case of James Bond, theyre usually very easy to identify with an almost cartoonish approach, see Jaws and Odd Job as examples, in the Zatoichi series, they tend to go for characters (or actors) that the Japanese audience identify with, Yojimbo (Toshiro Mifune reprising his role) for example. A big difference between the 2 franchises though is that the James Bond films have come to rely more and more on gadgets and overblown action sequences, the Zatoichi films rely far more on the storyline and characters.
There is a wry sense of humour in each of the original series of films which is why Takeshi Kitano was the perfect choice to take on the role for the 2003 film, by directing as well he has managed to successfully infuse some of his own ideas and personality into the Zatoichi legend.
I would definitely watch at least two of the original series before watching Kitano's version, just so you can get to know the character and be able to see the differences. Although the same actor Shintar Katsu played and indeed was Zatoichi in (I believe) 26 films! there were a number of directors over the years although I don't think any of them managed to achieve such a distinct style as Takeshi Kitano has.