There are variables to define the text length.
They should be localizable because the CJK (Chinese, Japanese, Korean) has double-width characters like Japanese Kanji and they are counted by chars.

• The text length of the excerpt.
• The text length of the excerpt in RSS feed.
• The text length of comment in dashboard.
• The text length of draft in dashboard.

My plan is that adds a number of text length into the .po to be able to localize.

These fixes are contained in the WP Multibyte Patch plugin with filter-hook in the Japanese package.