The fan group and doujinshi circle 07th Expansion, who appeared at Comic Market ("Comiket") 72 at the Tokyo Big Sight exhibition center on August 17, sold all available copies of its personal computer game Umineko no Naku Koro ni (When the Black-Tailed Gulls Cry) at its booth within thirty minutes. The game is the third part of the series that began with 07th Expansion's original PC game Higurashi no Naku Koroni (Higurashi: When They Cry). Read more
for Umineko no Naku Koro ni. And Wiki entry
for plot information.