Something's going down in Kamurocho. Sega appears to be planning some sort of announcement for the series, as indicated by all the construction work that's going on in the cityscape at the official site.
A video at the site recaps the series through Yakuza 4, and finishes with "And Then..." followed by the text "First look on May 24." This seems to suggest a long awaited reveal for Yakuza 5, which Sega announced months ago but has not fully detailed.
Yakuza games tend to debut in Famitsu. The next issue hits on the 24th, which presumably means we'll get early word of it on the announcement on the 23rd at around 8:30 or so in the AM (yes, we have our flying gets precisely timed).