The Japanese tree frog (Hyla japonica) is a species of tree frog distributed from Hokkaidō to Yakushima in Japan and from Korea along the Ussuri River to northeastern China, northern Mongolia, and the southern Russian Far East.Hyla japonica was formerly considered to be a subspecies of H. arborea (European tree frog). Animals from northern China, the Korean Peninsula, eastern Russia, and Mongolia have been considered to be a separate species H. ussuriensis, which would make H.