This is a "Kaiten Mutenmaru" lunch box, a prize from Kura Sushi's "Bikkura Pon" game. Rare Item: This lunch box is not for sale and is currently difficult to obtain, making it a rare item. Functionality: The lid can be removed for microwave heating. Accessories: Includes a rubber band to secure the lunch box. This item has been stored at home. Please understand that this sale is non-returnable and non-refundable. Thank you for your understanding.