Conversation so far:
What film work did Ryuichi Sakamoto do?
In January 2017 it was announced that Sakamoto would release a solo album in April 2017 through Milan Records.
Did he release any other albums?
the new album, titled async, was released on March 29, 2017.

Question: How did his career begin?
Self-contained rewrite: How did Ryuichi Sakamoto's career begin?