In Japan, manga magazines often find manga creators through contests that are open to the public—a convention celebrated in numerous manga, from Bakuman to Yoshihiro Tatsumi's autobiographical manga A Drifting Life.
Viz wants to see four-page storyboards on the theme of “The summer adventures of a thirteen-year-old teenager who dreams of becoming a movie star in New York,” and from glancing at the rules, it seems like it is OK to include Shonen Jump characters in the story. On the other hand, explicit sex, unnecessary violence, racism, promotion of alcohol or tobacco use, trademarks and characters that belong to other companies, and disparaging remarks about Viz are all verboten. That still leaves plenty of scope for creative minds, though.
The grand prize winner's story will be published in full in Shonen Jump and critiqued (privately) by a Shonen Jump editor. In addition, Viz is throwing in a package of manga drawing supplies, valued at $40. Three runners-up will get part of their storyboards in SJ, the critique, and the art supplies.
The prizes are more fame than fortune, but anyone who does this is a winner, because putting together a storyboard is a valuable experience. I was just chatting with the editor of a big manga publisher recently who remarked that when they look for artists, they look not at their stand-alone character designs but their storytelling abilities. Anyone can draw a perfect character, especially if they practice the same pose a lot, but making that character do something interesting—well, that's what separates the comics creators from the fan artists.
If you're thinking of entering, be sure to read the full rules, as they are fairly picky about the details of submissions. It would be too bad if you drew the greatest story ever, but the judges never saw it because it was an inch too large or you didn't include the correct information in the subject line. Also, be aware that if you win, your work will be deemed a "work made for hire," which means the Viz people can do whatever they want with it and you will have no rights to it.