Japanese font error in HTML mail

Even if setting a Japanese font in Mail, the software displays Chinese font like a following picture.

(1st word in the picture would be “今” properly in Japanese)

Of course, it displays properly in Inbox and Gmail web-client.
Could you please tell me any idea of mitigating or fixing this problem?
If you want me to send this mail, please let me know.

please send the EML file with this error to [email protected]
Also add link to this forum thread.
Thank you.