I don't see any post on JPHiP about this, but I could be wrong...
Takamasa Sakurai, who was a particular mentor to Wada Ayaka and also close to many H!P members, who was a writer about Japanese popular culture on the international stage, passed away two weeks ago after being hit by a train in Tokyo. RIP.
http://www.japantimes.co.jp/news/2015/12/04/national/japanese-pop-culture-expert-dies-railway-fall/I haven't seen any news about how this has impacted the H!P members, but I am sure Ayacho and many others must be devastated.
His personal facebook stops abruptly on the day of his death. It is at
https://www.facebook.com/takamasa.sakurai.77 and it has been renamed as a memorial site. One of his last posts was about the graduation of Kanon Fukuda from Angerme, but many of the posts were about his visit to Singapore just before his death.
I have read many of his writings, and I don't know of anyone who can fill the gap he leaves in the otakudom.