You must tag all tag spots, complete all Street Challenges, and get all the Graffiti Souls to unlock the Test Run in each specific area. In the Test Runs, you can unlock more characters.
Hidden Character A.ku.mu.
Earn a "Jet" ranking at Fortified Residential Zone.
Hidden Character Beat
Defeat him in a street race.
Hidden Character Boogie
She can be found at Kibogaoka Hill.
Hidden Character Clutch
Follow DJ Professor K's instructions.
Hidden Character Combo
Successfully complete his challenges.
Hidden Character Cube
Defeat the Noise Tanks At Sky-Dinosaurian Square, then go to the bottom of the Sewage Facility and defeat Cube in the City Rush.
Hidden Character Doom Riders
Earn a "Jet" ranking at Dogenzaka Hill.
Hidden Character Garam
Complete his challenges.
Hidden Character Goji Rokkaku
Earn a "Jet" ranking at Rokkaku-Dai Heights.
Hidden Character Immortals
Earn a "Jet" ranking in Skyscraper District and Pharaoh Park.
Hidden Character Jazz
Go to the future site of Rokkaku Expo Stadium. Defeat Jazz at City Rush
Hidden Character Love Shockers
Earn a "Jet" ranking at Hikage Street.
Hidden Character Noise Tanks
Earn a "Jet" ranking at Highway Zero.
Hidden Character NT-3000
Earn a "Jet" ranking at Sky-Dinosaurium Square.
Hidden Character Poison Jam
Earn a "Jet" rank in a test run at the Tokyo Underground Sewage Facility and at the bottom of Sewage Facility.
Hidden Character Potts
Earn a "Jet" rank at Kibogaoka Hill.
Hidden Character Rapid 99
Earn a "Jet" rank at 99th Street.
Hidden Character Rhyth
Go to the top of the Poison Jam warehouse in Rokkaku-dai Heights to find her the first time. Follow and find her two more times in the game.
Hidden Character RoBoy
Unlock A.ku.mu., then earn a "Jet" rank at Chou Street.
Hidden Character Soda
Defeat Soda in City Rush at Highway Zero.
Hidden Character Zero Beat
Earn a "Jet" rank in a test run at Shibuya Terminal.
