Legend of the River King (known in Japan as Kawa no Nushi Tsuri) is a fishing-themed role playing game series by Natsume (known mostly in America for its farming game series "Harvest Moon") that has releases on over 6 video game systems. Of these, 3 have been released in America, Kawa no Nushi Tsuri 3 and 4, dubbed "Legend of the River King" and "Legend of the River King 2" in the U.S. as well as Kawa no Nushi Tsuri: Wonderful Journey for the PS2 which was renamed River King: A Wonderful Journey. Natsume also plans to release versions for the Sony PSP and Nintendo DS.
In addition to the River King series which, as the name suggests, deals purely with freshwater fish, a spinoff series of saltwater fishing games has also been released called "Umi no Nushi Tsuri". The series has been released for the Game Boy, Super Nintendo, PlayStation, and Wii.