Joy Yanai was born in Quebec, Canada, and was raised in Sendai/Ishinomaki, Japan. She began taking cello lessons at the age of 5 in Japan before attending Walnut Hill School for the Arts in Natick, Massachusetts, in 2006. She earned her Bachelor of Music, Master of Music, and Graduate Diploma from the New England Conservatory, where her major teachers included Laurence Lesser, Paul Katz and Lluís Claret.
In 2011, Joy actively joined the Earthquake and Tsunami relief efforts for Japan both with solo recitals in the affected regions as well as performances in collaboration with such artists as Kim Kashkashian, Paul Biss, Laurence Lesser and Masuko Ushioda.
Joy participated in music festivals including Orford Music Academy, Banff Music Festival, Pacific Music Festival, Seiji Ozawa Music Academy Opera Project, Ozawa International Chamber Music Academy and Mellon Music Festival. She received First Prize for the New England String Ensemble Concerto Competition in 2009, Third Prize for the Junior String Division in Fischoff National Chamber Music Competition in 2010 and Second Prize for New England Conservatory Lower Strings Competition in 2014.