The fanclub just had an "upgrade", now if you want extra content you have to pay 6000 yen. You will receive goods, member card, novelty...
https://thebrilliantgreen.futureartist.net/fanclub
To be honest, I don't find the website even interesting so I'm not going to join at the moment. Another thing I find pretty weird is the fact that on february 6th last year we had an announcement for a new album for winter 2014-2015 and I really don't know what happened to that...a bit disappointed, hope they release it someday.