I plugged in "Takagi Masakatsu" into Last.fm (an artist I discovered from my FatCat inspired month), and took note of anything which tickled my fancy.
First of all, Sakerock blew me away. I could not stop listening to Kaishain (see video below). The rest of the album is excellent, too (but unfortunately not on Spotify).
I also discovered Cornelius, whose album, Point, is brilliant.
I've put together a Spotify playlist of this month's Japanese music, which also includes Sakura by Susumu Yokota. Enjoy!