Towards the beginning of the film, you have a scene that was often (too often) repeated in this series of films. It's very clever and funny, but was used in at least three different film--possibly more. It's where Ichi is the dealer with dice and "accidentally" drops dice out of the cup again and again--so the other gamblers know whether it will be odds or evens. However, using this ploy, he is able to film-flam the other gamblers by eventually dropping a much larger bet--at which time he springs his little surprise for them. Cute, but way overdone.
As a result of Ichi's gambling, a certain family is angry and set out to teach Zatoichi a lesson. In a tough scene to watch, they try to break his fingers. However, Ichi escapes and in a chaotic scuffle, he starts breaking their fingers again and again. While all this seems pretty funny, the end result is that an innocent and adorable little girl is accidentally stabbed in the foot. Tetanus sets in and unless she gets medicine, she will die. Of course, despite the cost, the good Ichi promises to somehow get the medicine and save the child.
Along the way, Ichi strikes up a friendship with a rather fierce ronin (a master-less samurai) who loves to play chess. Despite being a very tough character, he promises to go along with Zatoichi to protect him--mostly because this warrior is very taken with Ichi. Well, once again, Ichi does the same gambling bit he did at the beginning of the film, though things don't work out exactly the same. So, instead of a big haul, he and the ronin hit on another moneymaking plan. Thanks to their efforts, the medicine is obtained and the child quickly recovers.
Ichi accompanies the lady with the child to a nearby hot spring known for its curative powers. Now the child refers to Ichi as "Uncle" and he learns that the lady is not the child's mother but a relative who has taken in the child after the death of her parents. The lady also begins to show more than just casual interest in Ichi--after all, he's awfully lovable and women in quite a few films have tried to marry him. But, like Spiderman, he knows he can't settle down, as his lifestyle and idiots seeking him out for revenge make for a miserable and very short life for any woman. In addition, the woman holds on to a secret--something she only reveals to Ichi near the end of the movie.
At the spring, there are also two main characters who are introduced--a sickly young man and his sister who has traveled dressed like a man in order to come meet him. However, this plot point is kind of silly, as Kume is an exceptionally beautiful lady. Sure, she has her hair up in a ponytail like some men, but she is just too pretty to be mistaken for a man--even by Ichi! For some time you have no idea what they are up to, but Ichi knows it's something. After their servant is murdered, the young man divulges to Ichi that they have been tracking a samurai who murdered their father over a chess game and the servant was the only one who could identify the murderer. The young man assumes that now there is no way to find the killer, but Ichi realizes this sounds a lot like his new friend, the ronin.
Overall, this is one of the better Zatoichi films despite the repetitive gambling scenes. That's because the plot is very complex, relationships are stressed over the action scenes and there is no usual "boss battle" at the end of the film. Sure, there are a couple serious fights, but not the usual type nor does the film end exactly as you might assume. Very good stuff, here.