Eight years' worth of living expenses... a hundred and thirty grand? That's what, 16 grand and some change a year? Including uni fees for both of them? I know this is Japan where the cost of living and uni fees aren't through the roof but still, I do agree with him that they're probably gonna need supplemental income.
so for reference, my expenses doing my Master's in Fukushima were around 120k JPY a month, plus 265k JPY a semester.
so, assuming that rent is paid for:
100,000 JPY a month for food for 2 people (i'm being generous here)
15,000 JPY a month for utilities
30,000 JPY a month for entertainment
20,000 JPY a month for transport (assuming bus pass or such)
10,000 JPY a month for phone
first 4 years is high school: 8.4 million
Next 4 years of college: 8.4 million
4 years of college tuition for 2 students: 4.24 million
total: 21.04 million
This budget can be trimmed down, and it assumes expenses similar to Tokyo.
It also ignores scholarships etc, and other expenses, but is a rough calculation.
I didn't adjust for inflation because it's only recently that Japan has been experiencing inflation, till now the yen has been fairly static.
so, not unrealistic.
edit: if he does side work for extra income, if we take my limit of 28 hours per week, with a minimum wage of 1200 JPY, we get an additional 145,600 JPY a month, aka rounded up 14 million yen in 8 years. that's enough to cover main living expenses, and then the 20 mill can be sued to cover so much more.
heck, could easily get a solid headstart on a house.