>>11430766
What's funny is that the jumpsuit is straight from the comics- and even the hair in the show is just based off this cover of the 2nd printing of issue 2. But Fred-Wolf tried to sue Eastman and Laird and among one of their claims was inventing April's jumpsuit look.
Peter Chung was the one who adapted the design to animation. Years later, David wise claimed he based her off Fujiko Mine in a one of the last Lupin III part 2 episodes, which while notable for being directed by Hayao Miyazaki, was probably him lying.