The Japanese Flash (Rapala arata) is a butterfly of the Lycaenidae family. It is found from in Russia (Amur, Ussuri, Sakhalin and the southern Kuriles), north-eastern. China, Korea and Japan. The habitat consists of brook banks, meadows and the edges of montane mixed forests. The length of the forewings is 14–17 mm. The upperside of the wings is dark-violet with a dark outer border. Adults are on wing from late May to late August in two generations in the southern part of the range. In the north, there is one generation with adults on wing in June.