A manga work that Tezuka made when he was only 10 years old. Finally discovered and collected by 888 Books (who handles Yoichi Yokoyama's Gekiga) and published mid 2022.

(from fukkan.com)

A major event in the history of manga!
Many of the fantastic studies drawn by the young Osamu Tezuka are finally revealed in their entirety!
All works are included for the first time in a book, the ultimate collection of Tezuka manga that no one has ever seen before!

About this book:
　
This book is a collection of Osamu Tezuka's treasured manga, mainly "Mama Detective Story", which he made between the ages of 10 and 15. It is a collection of existing short and medium-length stories featuring the mysterious creature "Mama", some of which have been published and exhibited in mooks and exhibitions, but the full story has remained unknown.　
Since his debut work "The Diary of Ma-chan" Osamu Tezuka published numerous works throughout his life, but the creation itself dates back to his earlier childhood.

Although his drawings were initially done in the style of reproductions and kamishibai he created original characters as early as when he was in elementary school.

Especially famous are the many unidentified and mysterious creatures that interrupt the panels without regard to the development of the story, the first of which is the Hyotantsugi, followed by the mysterious "Mama" creature, which leaves a strong impression on the reader.

In "Mama Detective Story" which the young Tezuka drew for several years starting in 1938 when he was 10 years old (two works in existence), Mama played the leading role in an imposing manner and displayed a detective-like quality reminiscent of Mr. Mustachio who followed.