The practice of growing square watermelons is popular in Japan and aims for storage efficiency, cutting and ease of transport as it does not roll.

Square watermelons come from ordinary watermelon seeds that are placed in boxes as they grow. In Japan, these square watermelons are in great demand as decorations and gifts, costing about USD 100 or IDR 1.4 million per fruit, many times more expensive than ordinary watermelons. Because they are harvested before they are ripe, square watermelons are usually less suitable for eating.

The city of Zentusji in Kagawa prefecture is the center of Japan's square watermelon industry. According to reports, this idea was first developed by a local farmer in the 1980s. In 1978, a Japanese horticulturalist and artist named Tomoyuki Ono exhibited the watermelon for the first time at a gallery in Tokyo's Ginza. He also applied for and obtained a patent in the United States.

Since the appearance of the square watermelon, other watermelon shapes were introduced, such as the heart and pyramid shapes.

In Japan, you can buy square watermelons at some well-known supermarkets and fruit shops such as Sembikiya and Nishimura Fruits Parlor.