This is a mug from Sukoshiya, a Tobe ware pottery. They hold events nationwide, feature works by designers, and have previously produced tableware for Studio Clip. It's a stylish and popular kiln that has even been used as props in TV dramas. Each piece is handmade, giving it a unique character. Unlike typical Tobe ware, the texture is soft. I love this mug, but I have too many, so I'm letting it go while it's still in good condition. Tobe ware uses pottery stone, so I believe it's porcelain, but the texture feels like semi-porcelain. I'm sorry, but I don't know the specifics. As you can see in the third photo, there are black spots inside. I couldn't photograph them well, so they look blurry, but they are distinct iron particles, about 1mm in size. Height: 7cm Diameter: 9cm