That's good games, but half of the series are more than 15 years old... I don't see any change in the current trend : the japanese game series last long but died one by one (and I do think that's because the quality is declining at least compared to other games, compared to what the hardware can handle, and last but not least compared to previous games), and it concentrates more and more on the very few big series. I mean, what is Konami nowadays, a one game company ? What happens right now is that they can't even compete for launch games, they are late, can't take the risk for a tiny market, and have thin chances compared to bigger games... so, the few of them just come at the same time, more than one year after launch.
And in term of game fun, I really loved Yakuza 2, then the 1 was fun but still very similar, then the 3 was very disappointing... because it was absolutely the same game, the same places, the same gameplay and the same PS2-like limitations (map size, no car, collision test, interactivity) for the 3rd time. I didn't even played the 4... Tried the zombie version, it was utter sh*t. And more than anything, they killed my so loved Biohazard serie, the Team Ico could not produce anything in an entire generation, Sega Rally was just so bad and outdated, FZero was killed, etc. Yeah, definitely, I'm less and less excited by japanese games, and not really pleased to say it... I mean my train is direct to akihabara, I'd love to go there and see stands full of games I want to play. Anyway, it's good for you if you are still excited !