誰のパスポートの話か分からないけど(旦那さん?子供さん?ご本人?)、そんな大事なことご自身で調べないの?上手くググれないの?
ネットが無理でも、在カナダ日本大使館/総領事館に電話すれば一発で分かるよ?日本語はできるんでしょうから。
もうちょっと頑張ってみようね!
で、答えはコレ↓(在カナダ日本大使館HP【FAQ】より)
Q.
I would like to visit Japan for 10 days from April 8 - 18. My passport is valid until June 3. Does my passport have to be valid for at least six months after my departure date (April 8) as an entry requirement?
A.
No. Japan does not require certain conditions concerning your passport’s validity. While it is better to have a passport which is valid for a longer period than six months, as long as your passport is not expired when you depart from Japan there should be no problem with your entry into Japan.
http://www.ca.emb-japan.go.jp/canada_e/VisaTravel/FAQ.html