Nakayoshi is trying to stem manga's recent decline in popularity.
Total sales of manga magazines last year decreased by an estimated 5.2 percent from 2011, according to The Research Institute for Publications. Industry circulation fell by an estimated 6.4 percent from the previous year.
"Amid the low birthrate, all manga magazines are going through difficult times now," said Ikuko Nakazato, chief editor of Nakayoshi. "We're the oldest existing manga magazine in Japan, so we want to discover new talent and revitalize the market with a sense of mission."
Based on the value of the contents, the issue with the supplement should have cost at least ¥1,000, or more than $10. However, the March issue carried the normal price tag of ¥580, or about $6, to help entice readers.
The contest was conceived as "[the editorial department] thought that beginners who don't know how to storyboard might want to draw a one-page illustration," according to Nakazato.
Nakayoshi received about 500 entries, nearly five times the usual number for a contest.
The magazine plans further supplements. Its September issue, which goes on sale in August, will be sold with kits for color illustrations, a bonus feature for manga, which are mostly published in black and white. In early autumn, a book on how to get started as a manga artist will be published. The magazine also plans to start online manga classes.