Japan's tropical south — Miyazaki and Okinawa — grows tree-ripened Irwin-cultivar mangoes under glasshouse care; Miyazaki's 'Taiyō no Tamago' (Sun's Egg) is the country's flagship luxury fruit.
Japan is a small but disproportionately influential mango producer. Cultivation is concentrated at the country's tropical southern edge — Okinawa's main islands and Kyushu's Miyazaki Prefecture — where commercial production began only in the 1980s after greenhouse and grafting techniques made tree-ripened mangoes viable outside the tropics.
The dominant cultivar is Irwin, a Florida-bred red-skinned variety adapted in Japan to glasshouse growing and net-cradled tree-ripening (the fruit is allowed to fall when fully ripe and is caught in netted bags before it touches the ground). Miyazaki's premium grade — Taiyō no Tamago, the Sun's Egg — requires a minimum 350g weight, brilliant red skin coverage over at least half the fruit, and sugar levels above 15° Brix. Top-grade individual fruit routinely sells for ¥10,000–¥50,000 in department-store gift sections; record auctions have cleared ¥500,000 (US$3,000+) for a single mango.
Japan's mango culture is overwhelmingly gift-driven rather than everyday. Fruit is presented in lined wooden boxes for ochūgen mid-summer gifting, served in luxury fruit parlours over shaved-ice kakigōri, and used as a benchmark for what tree-ripened, glasshouse-precise mango cultivation can achieve. Season runs roughly April through August, peaking in May–June for Miyazaki and June–August for Okinawa.