Merry Noise were an electronica duo from the early 80s that consisted of Fumitoshi Ishino and Hidehiko Yoshino. The music they put out consisted of proto-IDM, ambient, experimental, and synth-pop. I don’t know if this stuff was ever officially released, but it has been uploaded by Takkyu Ishino (Fumitoshi Ishino) on YouTube.
The tracks range a bit. There’s some tracks that sound a lot like IDM (but came before IDM got started), these tracks feature drill n bass-style percussion, and IDM melodies and elements, but have that 80s underground Japanese experimental flare to them. There’s also some experimental / experimental ambient tracks. These ones sound darker, and are also pretty cool. There’s also a Depeche Mode cover present in this batch of songs.
Listen to these awesome tracks here