No these bikes were made for the North American market during the "bike boom" in the 1960s and 70s, to compete against more expensive bikes made in North America and Britain. So they were part of the massive growth of Japanese exports, along with transistor radios and Ibanez guitars. That style of bike is known as a sport-tourer, for recreational riding rather than racing or utility.

I suspect the rack was added later and it doesn't fit properly because the brake gets in the way, or some other attachment problem - also the rear triangle is short so the rear wheel is in very tight and so even if the rack could be leveled there won't be much heel room with panniers.

I don't think there is a bent top tube - that may be an illusion created by the top cable. and the head tube looks okay and directly in line with the fork - it just has a steep angle a bit like a track bike, which makes steering quicker, but is not necessarily the best for carrying loads.