Konami's CCG Yu-Gi-Oh! Duel Links has achieved four million downloads in its first week of launch in Japan.
The game was officially released in Japan on November 17th. An English-language version has also been soft-launched in Australia.
Konami claims that "many people have played the game every day", with 100 million duels racked up since the game's launch.
The game had hit three million downloads as of November 22nd, meaning it took just two days for an additional million downloads. Konami is running a special campaign in the game to thank fans for surpassing the three million mark.
Konami's mobile sales are often propped up by the success of baseball game Jikkyou Pawafuru Puroyakyu, which surpassed 26 million downloads in the third quarter of 2016.