One year after the failure of his first manga, Awawa World, Toriyama once again tried his hand at manga creation for the Monthly Young Jump award and crafted Mysterious Rain Jack, a one-shot mystery comedy that features an unnamed detective and his bumbling inspector ally who try to crack the case of a string of mysterious thefts that revolve around various items such as sweets and Cola. The story notably features character designs and scenarios that would later find their way into his most popular work, Dr. Slump. In particular, the lead detective's design would eventually be reused for Kurikinton Soramame and there's an appearance by an ogre who would later become Thunder Ogre Goronbo.

The work was unfortunately rejected which was in large part due to the usage of several designs lifted straight from the space opera film Star Wars. Despite this however, Kazuhiko Torishima, who would later become Toriyama's editor, contacted him with words of encouragement that kept him going until he eventually found success.

Like Awawa World, this manga would be republished in two parts in the "Bird Land Press" fanclub newsletter and would have its master materials brought out for display during a roaming art exhibition in the 1990s that was dedicated entirely to Toriyama's work. Unfortunately it along with Awawa World had its master materials stolen and when coupled with the use of copyrighted designs? This means an official rerelease is highly unlikely.