When I search for flights from South Korea to nearby countries on Google Flights, there are usually many flights from airlines which don't share fare data with Google, for example: T'Way, Eastar Jet, Jin Air, Jeju Air, Korean Air (see picture).
For Google Flights, this is an unusually large amount of airlines with unavailable price data (on most searches, there are just one or two with unavailable prices). Is there a different English-language meta-search engine with good coverage of South Korean airlines' fares?