What are their song lyrics about, and what themes do they explore?

I’ve been listening to them for a long time, but I haven’t really looked into the translations. I did try, but the translation tools do a very poor job of conveying the meaning from Japanese into Russian (my native language).

How are their lyrics generally perceived? What kind of emotions do they evoke? Are they more literary, or are they full of slang? Are they glamorous or simple, down-to-earth? Bold or gentle? Sarcastic? Are there any English-language bands they could be compared to?

In short, please describe everything you associate with their lyrics and the feelings they stir - I would be very grateful.