Watermelon is an ancient horticultural crop that is considered to have originated  in northeastern or western Africa and has been cultivated for over 4000 years. This crop  was introduced into Japan between the 16th and 17th centuries, and nowadays, it is almost  exclusively used as fresh dessert fruit in the country. The fruit flesh of watermelon contains  vital health-benefit compounds including lycopene, citrulline, arginine, and so forth. Despite  having much value, watermelon cultivation has shown declining trends in the past several  decades. Watermelon breeding in Japan has focused primarily on improving fruit quality  traits such as sugar content, flesh texture and color, and rind color or pattern. Moreover, a recent trend has been to develop small-fruited cultivars with high market acceptability. In this paper, we review literature to provide an overview of commercial production, cultivation history, and farming practices of watermelon in Japan. The paper also describes the agronomic characteristics of representative cultivars.