Gakuen Music High School, and at the same time won a special scholarship from the music department of Toho Gakuen School of Music.
He studied in the soloist diploma course at the School, and then studied under Elisso Virsaladze at the Moscow Tchaikovsky Conservatory winning a scholarship from the Rohm Music Foundation, and graduated from the Conservatory in 2015. Numasawa won Third Prize at the International Music Competition Cologne, First Prize at the Schnittke International Competition, and the Pozzoli International Competition that Pollini won before. Martha Argerich says that Numasawa is a wonderful and promising pianist and she was moved by his special musical sensibility and devotion to music. He has performed with numerous prominent orchestras and participated in prestigious music festivals inside and outside Japan and in Europe, such as La Folle Journee and Beppu Argerich Music Festival. Numasawa has been teaching at Toho Gakuen School of Music since April 2017.