Toon-Doku is a 2007 sudoku puzzle video game developed by Dragon's Den Unlimited and published by Majesco Entertainment for the Nintendo DS.

[2][3] One of Toon-Doku's main gameplay points is the player's ability to draw custom symbols for use within the games puzzles.

[5] Levels in the stage mode end with a boss fight, where an enemy can hide some of the boxes in the player's grid.

[17] Jeuxvideo.com's Jihem was more positive towards the use of symbols, while still writing that the idea wasn't original, due to it being used in children's newspaper, as well as another sudoku Nintendo DS game, Zendoku.

Eric Bratcher of GamesRadar described the controls and interface as "clunky", in addition to criticizing how it's hard to tell which symbol is which, due to the Nintendo DS' "fuzzy screen".