Shinsou Kaimei Dokuhon

Umineko no Naku Koro ni Shinsou Kaimei Douhon (うみねこのなく頃に真相解明読本) are a series of guidebooks written by KEIYA and published by Futabasha. Each book goes into detail regarding the individual episodes of, including fan theories, notes from Ryukishi07, and other materials.