I am also curious about the 6:6 or 7:7 course load for tenured professors (foreign and non-foreign) that the article implies is standard in Japan.
As each class only meets once per week for 90 minutes, a typical 6-class load translates to (assuming my math is correct!) just nine hours total in the classroom. Moreover, that 6-class load will normally involve just 3-4 preps, with permanent (tenured) faculty pretty much guaranteed the best classes. I.e., your teaching hours will be the least of your problems. (On the other hand, the meetings can be a killer--I spent over 6 hours in a single faculty meeting on numerous occasions.)
Regarding academic apartheid, I'd argue that things have gotten both better and worse. If you are a foreigner with a PhD, multiple publications and (most importantly) Japanese language ability, there seem to be far more permanent/tenured positions available than, say, back in the late 90s. Keep in mind that many of the better posts for foreigners (especially in the humanities) are advertised only in Japanese.
However, many Japanese universities still hire foreigners only to contract positions, with lower salaries, higher teaching loads, no research funding, etc. Often, these contracts are nonrenewable, or renewable only once or twice. Worse, and again especially in the humanities, you will now often see ads demanding PhDs (or MAs with numerous publications) and
extensive teaching experience and
Japanese language ability from applicants for even these inferior positions. I find it sad that somebody with these qualifications would take a position at half the salary (and twice the workload) of their Japanese colleagues, but in this economy, even an inferior job is probably better than none.
Note, though, that an increasing number of Japanese universities have begun hiring Japanese citizens to these inferior positions as well. Economic and especially demographic issues (e.g., the rapid decline in student numbers) are the main culprits.
My two yen, at any rate.