Tsunagi, Japan offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Tsunagi, Kyushu, Japan, is known for the Tsunagi Onsen, a hot spring resort offering scenic views and traditional Japanese hospitality. The best time to travel to Tsunagi, Japan, is in late spring (May), when the average air temperature is around 18°C (64°F) and the water temperature is approximately 16°C (61°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!