I got to wonder this (not yet ready for task because it's merely a question for now) -- what I know for being Korean is that 240 chars can be calculated differently, depending on the languages and scripts used. For example, Twitter used to have uniform 140 chars limit for everyone, and then later they added another 140 chars for non-CJK Languages.
So, the real question is - "How is the 240 chars limit calculated? Is it same across all languages? Or is it different per languages and maybe needs some modification per languages?"