Japanese imperialism before and during World War II was a product of the nation's struggle to grow and become an economic power. Less than 100 years before, Japan was a feudal state with samurais and shoguns. The nation grew up too quickly and wasn't ready for a modern world. Now, the nation has been stable for nearly 70 years. The atrocities committed during World War II were exceptional and not normal--Japan can have a full military again since it is one of the world's largest economies. Expanding its military can only help the global economy as the nation will need to purchase military hardware from some other country.
No, Japan should not remove its limitations on its military, because a limited military in Japan is still important to world peace. In World War Two, the atrocities committed by Japan, working with Germany, were grave. It is important that Japan's military not be allowed to rebuild itself so that this kind of loss of human life does not happen again.