Sudoku is truly a game for your smarter board game players. What makes the game sudoku "Japanese"?
The game was invented in Japan, so inherently a Japanese game and Sudoku, even when using the English spelling, without Japanese characters, sounds Japanese. We don't have any Sudoku games in Japanese on this site, however, the game mostly uses numbers for pieces. You might be able to find the rules in Japanese if need be.
Japan has won the World Sudoku Championship six times, in 2007, 2012, 2014, 2015, 2018, and 2023. This makes Japan the most successful team in the event, which is organized annually by a member of the World Puzzle Federation. The first World Sudoku Championship was held in Lucca in 2006, and the event has been held alongside the World Puzzle Championship since 2011.