On 14th September 2015, a tweet on the official Nogizaka46 twitter account confirmed the release of 8th November 2015 release of the documentary Kanashimi no Wasurekata (悲しみの忘れ方) : Documentary of Nogizaka46 in Blu-ray and DVD format.
Earlier in May, the official Nogizaka46 YouTube channel released a trailer of the documentary, depicting member comments on the various performing mediums the group has dabbled in, such as their lives and variety programmes.
Each format will come in two versions: Complete Box and Special Edition. Interested buyers can pre-order the CDs at CDJapan via this link.
Source: AKB48 Daily