Ah, it's an ancient Chinese character, just like the ancient "well". Japanese pronunciation is: 丼 (どん), which can refer to the tableware for holding rice or noodles, also known as 丼 bowl; Things, Japanese people's cooking with bowls of rice covered with various ingredients; The other is the sound made by a drip well. After the Tang Dynasty, the Japanese introduced China culture, which later means lunch box in Japanese.