In Higurashi no Naku Koro ni games, each chapter begins with a mysterious poem written by a person named "Frederica Bernkastel". Her poems summarize the theme of each chapter and these reveal some of what is going to happen in the following arc. The poem itself is quite meaningful as you play through each chapter.
The Comiket 62 version of Onikakushi did not have any poem, but the Comiket 63 version of Watanagashi included one for both Watanagashi and Onikakushi. These earlier poems are different from the ones that would appear from Tatarigoroshi onward, and only appeared in the Comiket 63 version of the games.
''Translations are from the AnimeSuki thread here. Translations for the C63 poems are from the Rena-Rena Toshokan blog.''