Just want to say that I really like Toyota machines and would snap one up in a heartbeat - they are so well engineered. I had the good fortune a few years ago to go on an industrial tour for 3 weeks in Japan that was hosted by Toyota - got to tour the different factories of Toyota Industries (so I guess I am a bit biased from my experience there) - learned about their history/dedication, their high standards and expectations - was very impressed with their many products. Before expanding to automotive and other manufacturing including sewing machines they were involved (and still are) in the manufacture of machinery & looms for the textile industry.
http://www.toyota-industries.com/corporateinfo/history/
I have an early Toyota serger that I love and would really like to have more of their sewing machines - have my eye on a '50s machine that recently came up for sale locally - just have to make sure I have the space.
All that said, I am not familiar with any other sewing machine manufacturing in detail, by other Japanese companies.