I appreciate that there were quite a few very nice Japanese made bikes in the 80's but the OP asked what brand ushered them in. That certainly happened well before the 80's.
Here's a comparison opportunity between my 1972 Fuji Finest (with several non-original components), and someone's 1971 PX-10. I don't think the similarities are accidental - especially as the PX-10 had been around for a few years by 1971, when I seem to recall reading, Fuji launched their upper-tier models.
