The ‘Tenth Anniversary’ booklet that came with games like King’s Quest had a page and a half dedicated to ‘A Short History of Sierra and Japanese Games’.
It states: By the time Sierra personnel got their first look at Silpheed, the Game Arts people and Sierra had cemented thier friendship. Sierra had hired not only Ed Nagano (Ken’s shopping companion on his first Japan trip) as a Sierra U.S. Ambassador for Japan, but also a Japanese programmer, Mickie Lee, for Sierra’s U.S. offices.’
‘Silpheed, which Ken licensed, was eventually released in April of 1989 for the U.S. market.’