Those who chose 20 million can't be serious.
I'll say 8 million as the absolute maximum. But it really depends on how well games like FF XV or Dragon Quest Heroes will hit the Japanese market.

I think you have to much faith in the future of Japanese console gaming. Why is there this weird conseption that games made in japan will somehow make consoles successful there. Those games will do better than western games, definitely, but they won't be turning the consoles around. The console market is dead over there and none of those Japanese-made games will change that. Not for any console.

I think it's just a culture difference. They just like the bite sized portable gaming experiences better than more dedicated console ones and are just not impressed by the differences that more power and a larger screen can bring to their gaming experiences. They just don't care about consoles.

its not about faith. here's how I see it.

I stand by the PS4 selling at least 8M in Japan and at most 10M. that's not turning around anything considering that at one point platforms sold as much as 30M over there. Now take into account that for majority of last gen the japs were a no show in game development. we hardly had more than 6 proper jrpgs or action adventure games from them. and fact is that those are the kinda games that the japs  play and will buy consoles for. This gen so far we have blooborne, Ff15, DQ and Persona already announced to be coming to the PS4. those games coupled with GT7 and MGS5 will push at least 3M consoles between them over there. then all that is left to be seen is just how many more Japan centric games are released for the rest of the gen. games sells consoles. you seem to forget that.

while what u are saying sounds accurate, the problem is that you are jumping the gun and don't really understand what is really wrong with the Japanese market. their apparent love for bite sized gaming is simply that, they just have gone to where the games are. the real problem is the jap  developers. you see, unlike western developers; who will make games and expect people to buy the console to play them, the jap developers want the console to have a sizeable install base before even supporting it. that was the problem last gen.  no install base, no games. no games, no one buys the console. the problem of the chicken and the egg. 

this gen, things already seem to be different. but it remains to be seen. the only way your theory holds water, is if in 3 years we have a glut of Japanese centric games and yet the console still doesn't sell there. then and only then van we say consoles are dead over there. but you're basing your theory on a problem that has a possible solution that is yet to be implemented.

I'd say 7M

Honestly, I think that western gamers care way more about those games than Japanese gamers do. I don't think Bloodborn will do much of anything in Japan in terms of pushing consoles. MGS5 definitely won't. Dragon Quest Heroes wont. GT7 won't. Kindgom Hearts definitely won't. 

FFXV will a little. You have to remember, that series is on a steady decline there and people are seriously overestimating how popular it still is over there. You know what significantly outsold it's best selling game, Final Fantasy 7, there? Dragon Quest. As in Dragon Quest 9. The DS game.

I'm not forgetting anything. "Japan centric games" are handheld games. Japan is caring less and less about home console gaming. It's less convenient and far more expensive than handheld gaming. This is a culture that still plays in arcades. Think about that. Think about why that is. They care so little about home console gaming that they'd rather buy coins whenever they want a gaming experience with more power, rather than investing in a home set up. Japan is actively regecting home console gaming.

I don't think anything will change that until maybe gaming becomes a paid for service. Then the PS5 is really just a subscription based streaming service, I can see some console games becoming a little more popular again. When Nintendo's handheld can play the next console's games on the go, I can see those "console" games becoming more popular there again. But physical home consoles? Never again.

whoa.... you're worse than I thought and I can now understand why reasoning with u is so hard.

so you don't think, MGS5, DQ, Persona and GT7 will sell consoles in Japan? Wow.

I don't think that's true at all. The PS3 had a ton of japanese-made games, but they aren't buying those games. Not like they're buying handheld games. It's not a chicken or egg situation. The trend went towards mobile gaming in Japan, so japanese devs started making mobile and handheld games moreso than console ones. And there's nothing "wrong" with the japanese market. There's nothing "wrong" with them strongly prefering handheld gaming.

Unless it's Pokemon. Then is really screws with my perfect console Pokemon game dreams.

It's just a culture difference, and one that is likely never going to change. And it doesn't need to.

15 million in 6 years, monster quest spinoff alone increased the numbers at 350%