So... this:
Worth noting - "Gao" (or whatever his name is) knows of Kiryu (this is noted in recent Gematsu updates). And you really can't ignore that striking resemblance to Lau who got shot in the head in Yakuza 3.
Then there's the master of the bar Ichiban and co frequent. Several people have noted his resemblance to Kashiwagi (I don't see it myself) and again, he was shot (many times) and is definitely dead. Like, super dead.
And then you have Han Jun Gi. In the main plot to 7 and was also shot in 6 (surely dead?)
So what's going on? The bartender might just be a coincidence, but Lau seems far to similar and well Han is totally in the main game.
Then you have Kiryu. He's not dead but he did leave at the end of 6. Under the seemingly normal story there's this weird undertone of death by gunshot here, heck all this weird stuff only starts appearing AFTER Ichiban himself gets shot. Who knows what's really going on but this is the most intrigued I've been with a Yakuza story maybe ever.