Naoki Urasawa has only won the Kodansha Manga Award once, which was in 1994 for "Monster". He has been nominated for the award several other times, but has only won once. The Kodansha Manga Award is one of the most prestigious awards in the manga industry, and it is given to manga that are considered to be of the highest quality.
Unraveling the Magnificent World of Naoki Urasawa: Test Your Knowledge on the Mastermind of Manga