I'm not quite 100% sure how to answer this #JMusicFriday theme of #ForTheNoob since the only thing I can think of to answer someone new to Japanese music would be to try to figure out what style music they like and suggest something I know of with that style.
I guess I'll go with this: https://www.youtube.com/watch?v=3bNpHADFGTY
Many people who don't know much about Japanese music assume it's all the stuff they know about in pop. Especially they might think of the super silly stuff like Kyary Pamyu Pamyu (who even made it into Simpsons...) I might like to introduce some people to the fact that there are all kinds out there, including this nice, somewhat grungy sounding rock, so I might introduce someone to something like this just to say "hey, it's not all silly pop!"