The light-hearted manga is about an adventuring samurai named Yaiba Kurogane (鉄 刃, Kurogane Yaiba?) who knows how to be a samurai, and little else. Yaiba lives with his father, Kenjurou, in the forest. One day, while Yaiba was eating, a troop of gorillas came to attack. Yaiba and his father escaped and hid inside a box, but they didn't know that the box was full of pineapples and was going to be transported into the city. In the city, Yaiba finds out that he is a legendary warrior and has to fight the evil of a demonic looking high-school student named Takeshi.

Yaiba adapted as an anime series that ran over 50 episodes, and encompassed the adventures Yaiba had in the first few runs of the manga. The show begins with Yaiba training to become a samurai in the jungle with his father and his two animal friends, Kagetora and Shonosuke. At a pivotal point, Yaiba's father announces that he is ready to return to Japan, and instructs him to find his old friend and rival, who just happens to be Sayaka's father.

The people that Yaiba meets along his journey to become a true samurai encourage him, train him, or inspire him to greatness, though at heart he is still a child, and his incredible skill with a sword is matched only by his kindness towards his friends. Though, he tends to leap before he looks, and his thick-headedness tends to turn potential allies into enemies, though his friends soon clobber him, and salvage the situation. This unlikely group embarks on a host of incredible adventures where they meet legendary figures from Japanese history, and finally overcome impossible odds, and put everything on the line, to save the entire planet from a threat not of this world. It's a story of love, friendship, hard work, and never giving up.