Retro Ninsei Sensu (Fan Design) Chawan (tea bowl). The artist's name is written on the box, but details are unknown. I think it's probably "Jyogaku". Size: Diameter: approximately 12.5 cm, Height: approximately 8 cm. It has a label from "Suminoe Shoten" (tea utensils), and judging from the ward name and phone number, I believe it's a tea bowl from about 40-50 years ago. It has been stored at home for a long time, but it is unused.