There is also much concern in Japan regarding North Korea and its nuclear and long-range missile capabilities , as a result of missile tests in 1993 , 1998 and 2006 and an underground nuclear test in 2006 . There are also controversies regarding North Korean abductions of Japanese , where Japanese citizens were abducted by North Korean agents between 1977 and 1983
underground nuclear test
2006 North Korean nuclear test
Anti-Korean sentiment