Personally, I think that the Japanese should have the right to let whoever they want into their country. If this means no one, then so be it. One supposedly negative effect from not allowing in immigrants is that the population will decrease. However, Japan has only a small amount of area, and yet 100 million+ people. It is already massivlely overcrowded. However, they are missing out on the positive economic benefits which immigration allows, such as a high proportion of working age people.