We do not have a word for “Grunge”. Then we can use “Kanji” to make a sound of the word. Japanese pronounce more like Gu-Lan-Ji.
The Kanji is a kind of characters that Japans adopted from Chinese in around the third century BCE.
Each Kanji has a meaning.
愚 means stupid. 乱 means rebellious. 児 means kid.
Yes, indeed.