Help with asian characters to avoid incorrect line breaking (mojikumi)

Well, mojikumi refers to character spacing for East Asian scripts. Kinsoku is what you're looking for, I think - it prevents certain characters from appearing at the beginning of a line. It's possible to set the composer to the J composer, and to select e.g. the hard kinsoku set with a script, but I can't guess what kind of script you'd need. One to edit all paragraph styles, perhaps? One that only applies the J composer and kinsoku settings to whatever paragraph you've selected? I can't guess. It makes me wonder what you're trying to do, and also why you're trying to do it when it's quite easy to use the East Asian toolset with an English interface. 

You'd have to test this one as I'm not 100% sure - @Peter Kahrel corrected me on unicode usage recently maybe has more insights here

Grep style and apply a no break character style

[\x{4E00}-\x{9FFF}\x{3040}-\x{309F}\x{30A0}-\x{30FF}]

This is a basic approach. It might not cover all complex line-break rules (especially punctuation and spacing) found in Asian typography, but it could help avoid breaking individual characters.