Bridgestone 'sneaker' folding bikes.
Bridgestone Bicycles
http://www.bscycle.co.jp/
Panasonic Bicycles.
http://www.panabyc.co.jp/
Tsunoda Bicycles
http://www.tu-bicycle.co.jp/
Maruishi Bicycles.
http://www.maruishi-cycle.com/
QBEI
http://qbei.jp/
Eirin is a popular chain of second hand (and some new) bicycles in Kyoto.
http://eirin.kyotocity.com
Kyoto Cycling Tour Project (next to Kyoto Central Station) 's page advertising some of their
ex-rentals cycles for sale.
http://kctp.net/jp/more/used