the musica transonic record that i have is probably the Asahito Nanjo record i have that I like the least, it's called Hard Rock Transonic.
Ohkami No Jikan are fantastic feature more or less the same musicians as high rise, musica transonic & mainliner, although they're more similiar to fushitsusha only less darkness more euphoria, look here:
http://www.fractal-records.com/04catalogue/catal_1.htm
Also Nanjo put out a record last year entitled Greed, which is rather appropriate if his reputation is anything to go by. It's a fantastic record though and limited to 250 copies so I'd recommend finding it before you can't.
Aural Fit, Doodles & Up-Tight are newer Jap-Psych bands who are great.
Other jap stuff i've been into recently and would recommend checking out, but isn't strictly psych rock, but is still out there is:
Yamashirube
Kuwayama-Kijima
Che-Shizu are an older Jap band that are psych pop, more than rock, but they're fantastic nonetheless.
And of course there's Fushitsusha.
Untitled PSF 3/4,
Untitled PSF 15/16 & Pathetique are easy to track down must haves, and all equally good starting points.