Amazon is not as big / important as in the West, but interesting too. In the first quarter 2016, many big games are coming in japan:
Street Fighter 5, Naruto UNS4, Star Ocean 5, Dragon Quest Builders,
Yakuza 1 Remake, Resident Evil Zero, Uncharted 4 and Dark Souls 3.
14x PS4 in the Top 20 on Amazon.jp (Japan), here are the charts / bestseller
In my opinion: 2016 is a big year for console-gamer in the west AND in japan. that sounds awesome : )