Yakuza Kizuna, in japanese Ryu Ga Gotoku Kizuna, was a mobile game published by GREE for iOS and Android as a spin-off of the Yakuza series.

It was a free-to-play social card game, but it closed after just 5 months.

This is a card battle game in which the player becomes a resident of the familiar "Kamimuromachi" and fights against foreign enemies that threaten him while cooperating with other residents. Familiar characters from the original will appear with a number of special moves.

In the game, while proceeding with requests from residents, collect and nurture fellow cards and build your own deck. As the title suggests, "bonds" are important, and not only can users form a "pole alliance" and fight against powerful enemies, but also fighting with friends will have a beneficial effect. If you show remarkable activity, you can move up to the top of the ranking and get the best reward.