MGQ3 Official Release Date
Going on sale in Japan on June 1st. So that means it could be anytime from around noon May 31st to noon Saturday the 1st for people in the EST time zone. So you could be playing it (in Japanese) in 8 days from now!
Source: Official site (「もんむすくえすと！終章」2013年6月1日（土）発売決定！)