Although Stephieku already answered, I personally got my FLOWER+poster from Toranoana. The deputy service I use is Celga, and they have no issues whatsoever with sites that also sell 18+ stuff (or even sites that sell 18+ stuff exclusively).
I recommend that if you follow an artist, check sites like Toranoana or CDJapan ASAP since they often have goodies. It's only that sometimes there will be different bonuses for other sites, in which case as soon as those first press goodies info comes out, make your choice quickly.
Re: FLOWER Poster
I recommend that if you follow an artist, check sites like Toranoana or CDJapan ASAP since they often have goodies. It's only that sometimes there will be different bonuses for other sites, in which case as soon as those first press goodies info comes out, make your choice quickly.