The Japanese government orders the Self-Defense Forces to intercept the North Korean rocket if its fragments are likely to fall within Japanese territory. http://www.japantimes.co.jp/text/nn20120331a4.html
The third and youngest of Kim Jong Il's sons, Kim Jong Un, is named vice chairman of the party's Central Military Commission, joining the party leadership and becoming his father's successor. http://www.japantimes.co.jp/text/ed20101013a2.html
A South Korean warship sinks in the Yellow Sea, allegedly due to a North Korean torpedo attack; 46 are killed. North Korea denies involvement. US and Japan agree to back Seoul. http://www.japantimes.co.jp/text/nn20100521a1.html
Defense Minister Yasukazu Hamada orders the Self-Defense Forces to shoot down any part of a North Korean rocket that might fall toward Japanese territory. http://www.japantimes.co.jp/text/nn20090328a1.html