Yeah definitely, you should have a bit of a break between each game.
They've just announced Yakuza 7 now and it doesn't seem like it's set in Kamurocho any more so that's different, it's set in Yokohama. Though, very strangely enough, they've decided to go for a turn based battle system. Which is odd considering the fighting mechanics in Yakuza are one of the best in video games.
It's set to be released 16th January, 2020 in Japan, South Korea and China with the English version later in the same year.