The overlapping circles design is known as Shippo-Tsunagi in Japanese.
It is a beautiful tessellation design created by a quarter of a circumference repeating the circle of the same radius and linking it in every direction.
This type of design is still used for the Japanese traditional crest.
Has a stainless steel infuser basket and baked porcelain enamel inside. Holds 20 ounces and is 5-1/2" in diameter.
Manufactured by Iwachu, in the Iwate region of Japan.
Click on picture to see detail.
Iwachu cast iron teapot warmer available.