In the Edo period, a large boat was operated on the Yodo River, which flows through Kyoto and Osaka, as a convenient way of transportation, and a small boat with food on it approached and said in the Kansai dialect, "Kurawanka, Kurawanka" (Would you like to eat?). That's where the name comes from. In order to eat on an unstable ship, a stable shape with a high bottom butt (high ground) was required, and it became the current form. It is also used in the Seto Inland Sea, and it is a traditional vessel that is made by passing down the custom to the present day. ・High ground and stability ・Thick, hard to crack and durable ・Easy to stack and store