Karashima began playing the piano at the age of three.
[1] He stayed in New York in 1973, but returned to Japan the next year.
[1] In 1975 he joined drummer George Ohtsuka's band.
[1] In 1980 he joined Elvin Jones' Jazz Machine, and stayed for five years, including for tours of Europe and the United States.
[1] He then switched to being principally a solo pianist, but also led a quintet from 1988 to 1991.