Mecha OST's are almost indebted to this guy. His work on Gunbuster, Raijin-Oh, G Gundam, GaoGaiGar, Exkaiser, Dai-Guard, Granzort, etc are all amazing. And while I may not have heard OP, I assume that's spectacular as well. Point being, he's a genius.
This guy is a wizard. He has written so many great soundtracks that, after I've listened through a number of them *once* he climbed to my most listened to artist, so I had to turn off scrobbling when I found some more works of his!
I was playing End of Eternity and I had to go look up who did the music. I had remembered that Sakuraba worked on it, but listening to tracks like "Home Sweet Home" made me question it. Sounded very inspired for a Sakuraba track! Indeed, it was Tanaka. Now I'm a fan!