In Japan, the traditional cast iron tea kettle, known as the tetsubin, has long been cherished for both its function and form. It is valued for its excellent heat retention, which is due to its thick cast iron body. The inner iron surface of the cast iron kettle absorbs chemicals in tap water, softening the taste and naturally releasing iron.

The tetsubin originated in the 17th century and evolved alongside Japan's tea culture. Among the most renowned production areas is Iwate Prefecture, home to Nambu ironware. These kettles continue to be crafted using traditional techniques while incorporating modern design, making them enduring in use and aesthetically pleasing in contemporary settings.