My Sensei, Osamu Tezuka

(from ebookjapan):

This is a short, 8-page per chapter depiction of the manga production process of Osamu Tezuka. The work depicts the events that took place during the three years or so that Mitsutoshi Furuya, a mangaka popular for such works as "Bar Lemon Heart," spent as Tezuka's assistant.

The work depicts the authenticity of legendary works passed down from generation to generation, stories known to no one, and Tezuka's private life in all its nakedness.