Theres a thread in the Artistic forum that explains how to get japanese text working on you computer, but if it turns out to be such a hassle, then is it really neccessary, just use romanji.
Oddly enough when I was making a stepfile with the title haruka kanata (which is what I put in the sm. text file) when I loaded stepmania it autoconverted it to kanji for me (遥か彼方) which was weird, but convient, but then I knew it anyway.
Simfile for those intrested, its good
http://www.bemanistyle.com/sims/simfile.php?id=6901