Sakata Gintoki is a samurai living in an era when samurai are no longer needed. To add to his troubles, oppressive aliens have moved in to invade. Gintoki lives with Kagura and Shinpachi, taking on odd jobs to make the world a better place... and to pay their rent.
Mondo Fujieda is in love with a girl named Izayo Gorugo. However, there's a problem: her family are all assassins. He ends up humiliating her and upon this humilation, she vows to kill him. Luckily for him she moves away. Years later, she comes back to seek vengeance, but what is a guy to do against a skilled assassin?