Rei (礼, Gratitude?) is the title of the fandisc game of the Higurashi no Naku Koro ni series which was released at Comiket 71 on December 31, 2006 as a token of gratitude to the fans of Higurashi no Naku Koro ni. The anime adaptation will be a series of five OVAs and the first episode will be released on February 25, 2009. It will contain both Saikoroshi-hen and Hirukowashi-hen while Batsukoishi-hen will be replaced by Hajisarashi-hen, a light novel included with the limited edition of the PlayStation 2 game Higurashi no Naku Koro ni Matsuri.

Source: Wikipedia