I don't believe Osamu Tezuka read Herman Hesse's novel Siddhartha. I say this because book 1- Kapilavastu of the Buddha series was massively disappointing.
I'm not certain how a writer, even a graphic novelist, can treat the subject matter with almost comical reverence.
It's likely I'll read book 2- The Four Encounters in hopes of redemption.
I believe women graphic novelists tend to write the most poignant tales while men graphic artist tend to draw the coolest shit. David B. can usually manage both though because he's a talented motherf***er.