The current Command Prompt cannot display and treat East-Asian (Chinese, Japanese and Korean) characters properly.
The monospace East-Asian character can have double width of one latin character. A character of double width, that is called as a "fullwidth" character, has double width of other normal characters (called as "halfwidth" characters). Actual width of one wide character can be retrieved by the wcwidth function (See wcwidth.c in console_test.zip).
If the output line has one character space remained and there is no fullwidth space, then one space blank is shown there and console goes next line.