If you have a Japanese PS3 account and have the free Toro app installed, Toro and Kuro visit Sega.
They spend some time with the Yakuza team and you see lots of pictures around Sega.
The cats dress like Kiryu and Akiyama towards the end and you also get a free autograph for your Toro homespace. Check it out, its pretty neat and its free.
Yakuza 3 and Kenzan are in the free archives. I think anything else is in the paid to unlock section which we can't purchase on an NA account. I'd need a Sony points card from Japan... or we wait 2 more years to go free (hopefully).