Real Neat Find! A Childhood Manga by Osamu Tezuka from 1937 when he was only in 3rd Grade!
Illustrations for a picture book called Little Mimi, the Hasty which I believe he also wrote.
Hello Again! Today here’s some drawings of American Cartoon Characters by Tezuka I don’t have an exact date but given the Krazy Kat dell comics design comes from 1951 I’d say around that time most likely.I love this piece because we get to see some cartoons beyond Disney and Fleisher he enjoyed: