Eiko Shimamiya (??????, ??????) (also called EIKO or PEKO), born April 20, is a female JPop singer and member of the production group I've Sound since their first album. She is best known for singing the opening of Higurashi no Naku Koro ni. Eiko also handles a school called Shimamiya Size (S-size) in Sapporo, Hokkaido, Japan.