I have read a few Tezuka works and this is probably the darkest one of those. Dororo is the story of a child whose organs sacrificed by his father to 48 demons for power. The child may have lost those body parts but not a strong will to live and with multiple prosthesis, survives to embark on a quest to recover those organs by slaying each demon for them. The name of that child is Hyakkimaru. Dororo is the name of the orphan thief who became his companion in that quest.
The manga is dark enough that the author adds a lot of puns, jokes, and fourth wall breaking references to add levity to it. It is not Tezuka's best work, part of it was the rushed ending due to cancellation. However, it is still better than most modern manga. Simply because he employed or originated a lot of manga tropes and storytelling techniques on display in this work.
The 2019 anime adaptation is the best way to enjoy this story. It fleshes out several of the background characters and adds more depth to the family conflict at the heart of it. The storytelling pace is resolved by reducing the number of demons from 48 to 12, allowing it to give it the satisfying ending it deserves.
If you still want to read the original manga, I suggest getting the all in one omnibus English edition by Vertical. It is a handy tome to have all of the Dororo chapters in one book.
