Yup, it hails from Naruto. :D Catchy as heck. XD For some reason, I'm using it to "judge" all of the theme songs that come after it, even though that really isn't fair. It's kind of why the 5th opening, "Seishun Kyosoukyoku" (Rhapsody of Youth) failed to meet my expectations. In retrospect, "Seishun K" is not a bad opening at all - "Fighting Dreamers" just seemed too awesome for its own good, or something; LOL.
Apparently, FLOW did another theme song for Naruto as well, so I'm anticipating how awesome it'll be...once I manage to catch up with manyNaruto episodes. XD
Also, if you loved "Go Go Power Rangers", this video features another Power Rangers theme made by the same artist, Ron Wasserman (also known as The Mighty RAW :D). Actually, I think this theme ties with both "Go Go Power Rangers" and "Fighting Dreamers" as well. ^^