Tailwind
Skymark is operating since 1998 and a Japanese passport NEVER been a requirement
As for a rating it is not important in Japan because you have to do an ATPL and a Type rating to obtain the Japanese license ( 5 to 6 months some time longer)
Flying times in Skymark is about 70 to 95 hours a month
Expect to work 6 days ON and 1 day OFF X 3 and you go on leave 9 days including your travelling time (use to be 10 days OFF a month and 24 days of annual leave on the first contract but they reduce it to 9 and 20)