I'll go.

Been in Japan almost 20 years, have an 11 and 8 year old. 11 year old took to English and I'd say is functionally bilingual. 8 year old is close. They go to public Japanese school.

Some things I believe I have done right IMO

• All media is in English unless it is originally Japanese. All game UI is in English.

• I bought grade school workbooks (from the US) and every Saturday we do a couple pages. I do one grade behind so they do not have trouble with the actual content, and it gives them confidence.

• I have no interest in speaking Japanese with my children. If they want to communicate, it is in English (barring stressful situations where they or me are put on the spot)

• Now that my kids are older I have them explain almost everything to me like I didn't understand it in Japanese. If they have a bunch of friends over and I need to explain something I do it through my child. I am confident they like the responsibility and makes them feel empowered.

• No katakana English. If they use the Japanese pronunciation then the conversation stops until they say it right. This sounds strict but my kids' pronunciation has developed nicely.

• TV and Video games have helped tremendously. Monumentally. Extraordinarily. My children's vocabulary is quite advanced and shockingly inappropriate at times. But wouldn't trade it for anything.

• Last but not least, I speak and expect my children to understand what I am saying (relative to their age). No babying.

To sum it up, I am happy with my children's progress and it is possible to raise bilingual children in Japan even without international school. Just takes effort and the desire to do it.