Oh, sure. this is the same document:
left side is the copy-pasted from gmail and it is legible.
the right is the print preview, and that is actually just what it looks like when I print it.
emeditor, version 8.05, running on winxp pro, SP2, with asian language pack and IME installed/enabled.
I usually add a bunch of line breaks and then print it out so I can add notes because I don’t read so many Kanji, and I have to look things up.
Which font do you use?
Can you try a proportional font, such as MS P Gothic or Meiryo?