Japanese letter is sometimes shown in incorrect way on xterm. In case that you use ubuntu with Japanese font. Here, I introduce how I made it available to show Japanese letter. (The way is also available for uxterm.)
Launching xterm with some option solves the problem. So, change xterm command on menu. If you use LXDE or Gnome etc., you can change menu with property window opened by right-clicking the menu. On the dialog, change the command to
xterm -fwb Sans, then wide bold letter displayed in Sans font,
In my case, I use openbox and wanted to change “Terminal emulator” menu item, which open LXTerminal, to xterm, then followed the steps below.
mkdir -p ~/.config/openbox
cp /etc/xdg/openbox/menu.xml ~/.config/openbox
Then I was ready to change menu and changed the execution command of “Terminal emulator” in
~/.config/openbox/menu.xml to xterm launching command with options.