Sega has announced that the Yakuza series has sold 7.5 million games worldwide. This tally includes the six canonical numbered games, the two samurai-era spinoffs, the two PSP spinoffs, the HD re-release pack of 1&2, and the zombie apocalypse spinoff. Of the 11 or 12 Yakuza games, five have gone stateside, and another is on the way. The five localized games do not include either of the two PS4 games.
The most recent release, Yakuza 0 for both PS3 and PS4, has reportedly sold half a million copies when you count both platforms and lump its Japanese and mainland Asia releases together.
Zero was the first Yakuza (or Ryu Ga Gotoku, as it's called in Japan), game to be released in mainland Asia and has thus far been a big hit.
It's not available in English, but Japanese and Chinese versions are available, and guides are starting to pop up all over the place, now that it's been out for a while. PS3 and PS4 are region free, so if you're considering an import, there's always Play-Asia.
