Born in
Tokyo, Ishii studied composition privately (with
Akira Ifukube and
Tomojiro Ikenouchi) and conducting with
Akeo Watanabe from 1952 in Tokyo. In 1958, he moved to
Berlin, where he continued his studies under
Boris Blacher and
Josef Rufer. In 1962 he returned to Japan . His music has been performed by the
taiko group
Kodo and he has composed for Japanese instruments as well as symphony orchestra and other Western instruments. In 1999, Ishii produced the opera
Tojirareta Fune. That same year Ishii received the
Medal of Honor with Purple Ribbon for his contributions to Japanese music. His father was the first recipient of the award 44 years earlier. He died in
Kashiwa,
Chiba,
Japan, at the Kashiwa National Cancer Center of
thyroid cancer on April 8, 2003, at the age of 66. ==Selected works==