Vespa simillima, including the subspecies known as the Japanese hornet or Japanese yellow hornet (Vespa simillima xanthoptera) (キイロスズメバチ), is a common hornet species in the Eastern Hemisphere. V. s. simillima (Japanese:ケブカスズメバチ, Korean: 털보말벌, "Hairy Wasp") is darker and hairier than V. s. xanthoptera. V. s. simillima lives in Hokkaido, the Korean Peninsula, Eastern Siberia and China. It should not be confused with the Asian giant hornet (Vespa mandarinia), whose subspecies V. m. japonica is sometimes referred to as the Japanese giant hornet. In Japan, V. s. xanthoptera is more common than V. s. simillima. In Korea, V. s. xanthoptera only lives in Jejudo.
This page contains full information about Japanese Hornet.