3nin Matsuri is the Hello! Project 2001 shuffle group consisting of Rika Ishikawa and Ai Kago of Morning Musume, along with Aya Matsuura. The name 3nin Matsuri literally translates to "3-person Festival".
They released the single "Kiss! Summer Party" on July 4, 2001, to great success, outselling the other shuffle units' singles in 2001.