Persist with touristy sites in Seoul / Busan and actually talk to people in their indigenous language and you won't have a concern. The layout is quite extensive so its not as claustorphobic as other clubs. Unsure about entry policy but recognizing Mass, it should be NOT foreigner pleasant (Except https://bookmarkstumble.com/story22145233/foreign-karaoke-gangnam-no-further-a-mystery