Mahjong Soul launches Sword Art Online crossover running into next month

Kirito, Asuna, Leafa and Sinon have dropped into Mahjong Soul with a deadline attached: the Sword Art Online crossover runs through May 13 at 5:59 a.m., and the useful rewards are spread across limited characters, Azure Expanse outfits and a pile of themed cosmetics.

The collaboration launched after maintenance on April 22, 2026, under the name Oath of the Sword. Mahjong Soul, developed by Cat Food Studio and operated by Yostar Games, is running the event on Android, iOS and PC through Steam, so the crossover is live wherever the game is already installed. For anyone logging in now, the first thing to notice is that this is not just a paint job on the lobby. The event puts four Sword Art Online names front and center, and that matters because Mahjong Soul has always leaned hard on character collection and presentation as part of its appeal.

The biggest catch is also the biggest sales pitch. The collaboration’s Azure Expanse outfits are limited-time, but they only work if you already own the matching character. That makes the crossover friendlier to players who already spend on the roster than to pure free-to-play accounts looking for a clean one-and-done pickup. The upside is that the collab is not locked to premium cosmetics alone. The update also adds a special event mode called Vulture’s Deal, which gives everyone something to do beyond chasing the rare pulls.

The themed rewards are where the crossover earns its keep. Players can chase decorations and effects built around Sword Art Online imagery, including the Floating Castle tablecloth, Heart of Clarity tile back, Black and White riichi bet, Fatal Declaration riichi effect, Eclipse of Interwoven Blades winning effect and VRMMO portrait frame. Those are the kinds of extras that actually move the needle in Mahjong Soul, where the table, the tiles and the call effects are part of the personality of a match.

The fit makes sense when you look at Sword Art Online’s reach. The franchise started as a light novel series in April 2009, its anime adaptation first aired in 2012, and by 2022 it had passed 30 million copies in cumulative global circulation. That is the kind of name recognition mobile games still chase, and Mahjong Soul has landed the crossover at the right moment for both existing regulars and SAO fans who may want in before the event window closes next month.