Edo is a city that was home to the vigor and ambition of samurai across the country. However, following feudal Japan's surrender to powerful aliens known as the "Amanto," those aspirations now seem unachievable. With the once-influential shogunate rebuilt as a puppet government, a new law is passed that promptly prohibits all swords in public.

Enter Gintoki Sakata, an eccentric silver-haired man who always carries around a wooden sword and maintains his stature as a samurai despite the ban. As the founder of Yorozuya, a small business for odd jobs, Gintoki often embarks on endeavors to help other people—though usually in rather strange and unforeseen ways.

Assisted by Shinpachi Shimura, a boy with glasses supposedly learning the way of the samurai; Kagura, a tomboyish girl with superhuman strength and an endless appetite; and Sadaharu, their giant pet dog who loves biting on people's heads, the Yorozuya encounter anything from alien royalty to scuffles with local gangs in the ever-changing world of Edo.