Ninja Fest (2006)

G4's Attack of the Show hosts Kevin Pereira and Olivia Munn broadcast a competition to ninja aspirees everywhere to create a video displaying their 'ninja moves'. Hundreds of people sent in submissions, and three finalists were selected. Through various competitions in America, the two winners were chosen; Collin Bell from Washington and Brett Sims from South Carolina went to Japan. They then participated in the Ninja Warrior Sasuke tournament.

Ninja Fest 2 (2007)

Once the videos were sent in, six finalists were chosen. The six finalists were: Russelis Perry aka "Blackie Chan") from Colorado Springs, Colorado; martial artist Joe Simonsen from West Islip, New York; Freerunner Brian Orosco from San Francisco, California; Rick Seedman from New York City, New York; freerunner Levi Meeuwenburg from Ann Arbor, Michigan; and Mark Witmer from Minneapolis, Minnesota.

These six finalists then went to a US Navy training camp, where they competed on a marine training obstacle course. In '1v1' challenges, three of the six competitors were eliminated. Once there were three challengers left, they competed on an improvised course consisting of several of the new Ninja Warrior's most difficult obstacles.

The winner, Levi Meeuwenberg, cleared it in 45 seconds, followed by Brian Orosco at 1:12 and Russelis Perry in third place at 1:16. In Japan the two top finalists Levi and Brian were joined by former finalist Brett Sims to take on the course at Midoriyama.

Ninja Fest 3 (2008)

The third American Ninja Challenge contest by G4 wrapped up in August 2008, and aired as part of November 12, 2008. Viewers got to vote for their favorite competitors and the top three would be picked and flown directly to Japan to compete in Sasuke 21. The three winners were Brian Orosco (who qualified with a different video), gymnast Mark Witmer of Minneapolis, Minnesota, and freerunner/stuntwoman Luci Romberg (the first woman to qualify) of Valley Village, California. These winners joined American Ninja Challenge 2 winner Levi Meeuwenberg and both hosts from Attack of the Show!, Olivia Munn and Kevin Pereira competed. In Japan, they have the ultimate experience, along with training at Muscle Park, a scaled-down version of the Sasuke course located in a section of the shopping mall called "Muscule Park".

Ninja Fest 4 (2009)

The fourth and final Ninja Challenge contest winner was David Campbell. He joined up with former Ninja Challenge winners Luci Romberg and Levi Meeuwenberg to compete in Sasuke 22. Also joining them was the returning host Olivia Munn for the run to the top of mount Midoriyama. This season concluded the American Ninja Challenge, which subsequently evolved into its own national format - American Ninja Warrior. Beginning with the 4th season of American Ninja Warrior, the qualifiers would compete on a replicated Sasuke Midoriyama course in Las Vegas, USA (and no longer participate in the Japanese version of the show). Beginning with ANW5, additional "Special" competitions would also be arranged between the finalists of the Japanese and USA editions of the show.