Eiko Shimamiya  

Eiko, whose real name is unknown but goes by the nickname PEKO or simply EIKO, was born on April 20th and is a female J-Pop singer associated with Ive Sound since their first album release. She gained popularity for her performance of Higurashi no Naku Koro ni's opening theme song. Additionally, she runs an educational institution called Shimamiya Size (S-size) in Sapporo, Hokkaido, Japan.