Tongpoo no Daibouken

The Adventures of Tongpoo is a one-shot manga by Akira Toriyama that was published in the 1983 52nd issue of Weekly Shōnen Jump and was later released in the compilation Akira Toriyama's Manga Theater Vol. 2.

Along with Dragon Boy, The Adventures of Tongpoo served as an inspiration for Dragon Ball. It is forty-five pages long, and it introduced an early concept of the Capsule as well as story elements for the second Dragon Ball chapter, "No Balls!"

(Source: Dragon Ball Wiki)