Eiko Shimamiya

She is also known as simply EIKO or PEKO Born April 20, she is a female J-Pop 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. [edited Wikipedia info]