DJ Professor K broadcasts the Jet Set Radio pirate radio station to gangs of youths who roam Tokyo-to, skating and spraying graffiti. One gang, the GGs, competes for turf with the all-female Love Shockers in the shopping districts of Shibuya-Cho, the cyborg Noise Tanks in the Benten entertainment district, and the kaiju-loving Poison Jam in the Kogane dockyard. The authorities, led by Captain Onishima, pursue the gangs with riot police and military armaments. After the GGs defeat Poison Jam, Noise Tanks, and Love Shockers in turf wars, they each drop a piece of a mysterious vinyl record. Professor K says that the mysterious vinyl has the power to summon a demon.

The GGs are joined by Combo and Cube, who explain that their hometown, Grind City, has been overtaken by the Rokkaku business conglomerate. They ask the GGs to help them to free their friend, Coin, who has been captured by the Rokkaku. The Rokkaku pursue the GGs and steal the vinyl record. Poison Jam explains that the Rokkaku CEO, Goji Rokkaku, plans to use the record to make a contract with the demon and take over the world. The GGs defeat Goji in the rooftop of his headquarters by destroying his turntable. Freedom is returned to the streets of Tokyo-to. Combo reveals that The Devil's Contract was an old record with no demonic powers and that wealth had driven Goji to insanity.