User blog comment:Jmcdavid/Was Ginga a Reverse Fourze?/@comment-5724614-20160401000748

Not much, but its succeeding series, Ginga S does share the same director, Koichi Skamoto. Tsuburaya crew however does acknowledges the fact that Ginga was meant as an expy to Fourze. Among the original plans are:
 * Ginga was meant to take place in the same universe as Ultraman Gaia. (Gaia is earth and Agul is sea, so that makes Ginga sky/space)
 * Gamu Takayama was meant to return in the series as a high school teacher and the protagonist is a high school student with Gamu makes him his mentor.
 * Hikaru Raido (age-wise) is indeed that of a high-school though because of his country of residence is England, that only makes his school's curricular/education system different from Japan.