Jang-Navi Mahjong Online began as an Au Feature Phone-exclusive title launched in September 2004, before eventually expanding to become an online mahjong game where players can compete across various platforms and devices, including Docomo, Softbank, Android, iOS, and PC (DMM Game Player). Switch version users will also be able to compete in online battles against users across all platforms. Developed under the supervision of mahjong pro Yousuke Ide, Jang-Navi Mahjong Online features various game modes and features, including “Rank Battles” in standard four-player or net-popular three-player mahjong with skill-based matchmaking, single-player CPU games, a replay mode to review past games, and “Jang-Navi-kun” mascot character designs from towns all over Japan.