The kid is seriously retarded. Someone mentions a word as random as Goomoonryong and you immediately say I don't know that person? Isn't it common sense (even a reflex) to say "What are you talking about?" when asked a question that you shouldn't answer? He must not read manga or watch TV. It happens all the time in those mediums, even if it ridiculous in real life.
Is his master going to rescue him? I doubt this will end with just a friendly chat.