Words from Nagai Go (excerpt from the introduction):
The same year as Barbara, Tezuka began serializing Black Jack, and the following year ('74), he introduced Black Jack's assistant Pinoko in the same work, which I think was the prototype for the two characters in Barbara. I think Barbara is a very significant work that marked a turning point in Tezuka's works. I hope you enjoy Barbara: Go Nagai Version, a new interpretation of Barbara in my own way.

(Source: Shogakukan, translated)