Artistic Director of Biwako Hall and Music Director of Tokyo Mitaka Philharmonia, Ryusuke Numajiri won 1st Prize in the Besançon International Competition in 1990. This resulted in invitations to conduct the London Symphony Orchestra, Montreal Symphony Orchestra, Orchestra Sinfonica di Milano Giuseppe Verdi, Orchestre National du Capitole de Toulouse, Orchestre de Chambre de Paris, DSO Berlin, Düsseldorfer Symphoniker, Staatskapelle Weimar and Darmstadt, Sydney Symphony Orchestra and China Philharmonic Orchestra. Since making his debut as an opera conductor in 1997 with Mozart's Die Entführung aus dem Serail, Numajiri has gone on to lead various productions at Cologne Opera, Komische Oper Berlin, Theater Basel, Bayerische Staatsoper, Opera Australia and New National Theatre Tokyo as guest conductor. In 2014 Ryusuke Numajiri composed an opera based on the famous Japanese folktale Bamboo Princess, also known as Princess Kaguya (Taketori Monagatari), which has been performed in Yokohama, Hanoi and Otsu.
A strong advocate of contemporary music, Ryusuke Numajiri recorded The Canticle of the Sun by Sofia Gubaidulina for EMI featuring Mstislav Rostropovich and the London Symphony Orchestra. He also directed the Japanese premieres of several major contemporary works including Philip Glass' “Peace Symphony”, Busoni's Piano Concerto and Doktor Faustus, Zemlinsky's Der Zwerg and Schoenberg's Notturno. He also introduced to the Japanese public works by Messiaen, Andriessen, Górecki, Ligeti, Lutosławski, Berio, Dutilleux, Xenakis, Birtwistle, Matthews and Rott.
Numajiri was awarded Medal of Honour with the Purple Ribbon by Emperor of Japan in 2017.