Very much alive, especially Kansai but of course Tokyo also, although it is much more modular synths and stuff like that over there I think. Labels to check out Advaita Records, La Muro Mia Muro, Remodel, Three Plugs Records. I made a longer topic on Kansai on the other forum but I just copypaste the names here;
Juri Suzue (cut up and noise)
Kurumi Kadoya (harsh noise)
din-i-lahi (harsh noise with metal junk)
KK Manga (loud noise band, intense and awesome every time)
Weiches Loch (metal percussion group that I also used to be in. Also almost every member of this group does lots of other stuff too so it might be a good rabbit hole to fall into)
Hako (experimental with wide range, lots of acoustic instruments and voice also)
Banetoriko (self-made springjunk, noisy dark ambient feel)
Mitei Narico (lots of effects, harsh noise)
Kayu Nakada (noisy circuit bending monster sculpture noise)
Kazue Asano (lots of self-built semiacoustic instruments, maybe more experimental)
Sun Sun Town (saddly not active now, but a great noise band with metal percussion, vocals and harsh noise)
Statuszero (harsh noise with lo-fi junk)
Masayoshi Sakaguchi (modular synths, but I think among the best ones in terms of noise)
Path (guitar noise from Wakayama)
Makoto Kikuchi (guitar and theremin, usually quite drone feel)
Fuji Yuki (vocal drone)
Kozue Sugiura (noise with mostly self made things and home appliances, for example vacuum cleaner)
Masataka Nagano (LOTS of effects, instruments and junk, noise)
Suchirusu (ambient with sitar and synthesizers, also participates noisier projects)
Kinzoku Taiko & Sandersonia (metal percussion and violin duo from Kyoto)
BBVGC (harsh noise)
Kanda Oboo (bass and vocals duo)
Misancholy (beat based and noisy music)
Yonju Miyaoka & Sayozoku (various things)
the descriptions are quite limited and most of these people do plenty of other things too but this should get you started, I have other things to do also.