Zatoichi is seemingly only a harmless blind bone setter who wanders around the country making his living by gambling ; however, he is also highly-skilled in swordsmanship , specifically iaido . He does not carry a traditional katana , instead using a well-made shikomizue ( cane sword ). Shikomizue were generally straight lower-quality blades which could not compare with regular katanas, but as revealed in Zatoichi's Cane Sword , his weapon is nearly superior to one as it was forged by a master bladesmith just before his prime.

A recurring theme of both the films and television series is Zatoichi protecting the innocent from oppressive warring yakuza gangs, and general injustice. His fighting skill is incredible, even more so considering he grips the sword in an inverse manner; this combined with his sometimes inexplicably keen ear, nose and proprioception renders him a capable surprise attacker. He is also most likely ambidextrous. However, for example in the 2003 movie, he can resume the traditional normal grip when necessary.

The character's name is actually Ichi . Zato is a title, the lowest of the four official ranks within the Todoza , the historical guild for blind men. Ichi is therefore properly called Zato-no-Ichi ("Low-Ranking Blind Person Ichi", approximately), or Zatoichi for short. Giving massages was a traditional occupation for the blind, probably because it can be done on the basis of touch.