The story follows Travis Touchdown, who is a stereotypical otaku – his motel room decorated with professional wrestling and anime collectibles – living in near poverty in the No More Heroes motel of the fictional town of Santa Destroy, California. After winning a beam katana in an internet auction, he runs out of money to buy video games and wrestling videos. After meeting with Sylvia Christel, he accepts a job to kill Helter Skelter, also known as "the Drifter," which earns him rank 11 by the United Assassins Association, a governing body of assassins. Realizing that he has the opportunity to make it to the top, he sets out to secure himself the coveted position of number one assassin in the UAA.
The game has a free roaming world, allowing Travis to move around on foot or on his modified scooter, the "Schpeltiger". Gameplay is open-ended, with the condition that the player must kill the top ten assassins to make the storyline progress. There are numerous part-time job side quests to earn money which can be spent on weapons, training sessions, clothes and video tapes. Money is also required to compete in a Ranking fight. Control is handled through the Wii Remote and Nunchuk attachment, with the Remote controlling his weapon, the beam katana, and the Nunchuk moving Travis. Most attacks are performed using the "A" button, with certain other moves, including the "death blow" and sword lock struggles, executed by following on-screen instructions.