Oonishi Aguri was born on May 2, 1997 in Aichi Prefecture, Japan. She is one of the original members of the idol group x21 who joined back in January 28, 2013, but left on April 16, 2017. She voices Rena, a member of seiyuu-idol unit SPR5 from Shoumetsu Toshi mobile game and TV anime. She also appears regularly in Seiyuu Paradise R magazine.