@passiflora The salary itself is alright but you should understand that a
good international school will cost closer to 2.5m a year. Nagoya International School is easily over 3m for elementary school with miscellaneous expenses. The 10m salary is not going to support that very easily.
I guess it mostly comes down to whether your wife can find a decent job, and whether you're dead set on international school. I should note that a shitty international school (common in the 1-1.5m range) can easily be worse off than going to a Japanese public school with supplemental english studies.