you are right it's a phenomime and adverb meaning sorry that they are adjectives misty hazy foggy murky gloomy and unclear usually the word is written ' ' with a small tsu the line can be translated as 'it something like your heart is shrouded by fog isn't it ' if you have dictionaries look up the word 'moyamoya ' the meaning is almost the same when you need japanese help don't hesitate to ask me