Takao Koyama has a Series Composition credit for Dragon Ball Z.
series composition
TV anime / 1982
script
TV anime / 1973
TV anime / 1980
Movie / 1986
TV anime / 1983
TV anime / 1987
TV anime / 2000
OVA / 1989
TV anime / 1984
TV anime / 1974
planning
Movie / 1992
TV anime / 1993
script (eps 1-3, 9, 12)
Special / 1985
Short TV anime / 1972
Short TV anime / 1992
TV anime / 1985
TV anime / 1996
script (eps 1-2, 15)
OVA / 1990
Movie / 2009
Special / 1981
Special / 1988