An upcoming Oxford University Press book about Leonard Bernstein by Mari Yoshihara, a Japanese-American academic, will focus on one of the conductor’s and composer’s love affairs, The Guardian reports. Bernstein met the Japanese Kunihiko Hashimoto when he was visiting Tokyo with the New York Philharmonic in 1979. Yoshihara found some 350 letters at the Library of Congress in Washington relating Bernstein’s relationship with the younger man, which lasted about 11 years until the summer of 1990, a few months before Bernstein’s death at the age of 72.