Based in Tokyo, Shotoku Glass (松徳硝子) was established in 1922 as a lightbulb manufacturer. As the lightbulb industry became automated, Shotoku Glass turned its mouth-blown glass skills to producing glassware. Shotoku Glass is renowned for its collection of especially thin glass, named Usuhari (うすはり).
The Shotoku Glass furnace burns 24 hours a day, 365 days a year, always between 1,300 and 1,500 degrees. When the artisans finish their work at 17:00, the craftspeople that specialise in melting glass arrive to carry out this process throughout the night.