'Yotsuboshi', a seed propagating type F1 hybrid strawberry cultivar adaptable for year-round production, was developed from the collaborative breeding program including four institutes of Mie, Kagawa and Chiba prefectures and National Agriculture and Food Research Organization (NARO) in Japan. The behavior of flower initiation is quite unique. 'Yotuboshi' exhibits stable extra earliness under natural condition with a lower temperature and shorter day-length, while it possesses the ever-bearing gene which results in the induction of flower initiation under long-day condition. Thus 'Yotsuboshi' is adaptable for year-round production including both forcing culture in autumn to spring and summer-autumn cultivation across Japan. 'Yotsuboshi' has several attractive traits such as a clear red fruit color, excellent fruit shape and size, high yielding ability, and superior taste with a high content of sugar and moderate acidity. The practical production system of F1 hybrid seeds and the DNA marker system for certifying the uniformity of seeds have already been established. The seeds and/or plug tray seedlings will be commercially provided from this summer for the member of the 'Research society for seed propagating type strawberries in Japan'.