Answer:
North Korean missile tests are a major matter for Japan because the missiles sometimes fly through Japanese airspace and territory.
Step-by-step explanation:
There have been various encounters between the two countries over the North Korean secret exercise in Japan besides the abductions including Kidnappings, spying, marine poaching, and drug bootlegging.
North Korean missile tests are a major matter for Japan because the missiles sometimes fly through Japanese airspace and territory. and increasing military power of North Korea threaten not only Japan but also various neighboring countries including South Korea plus both countries Japan and Korea have historical rivalry as Japan was the colonial master of Korean Island once.