There are many illegal immigrants in Korea recently. Should we allow them to stay in Korea or not?

There have been cases of undocumented illegal immigrants in Korea recently with the Korean government actively looking for solutions to curb this. Most of the illegal immigrants are low wage workers with their labor's three primary rights not strictly granted. Most of them want to stay longer than the legally allowed period and eventually get Korean citizenship. Personally,I do not see any problem allowing them to stay in Korea and give them citizenship. The reason is Korea needs them. Someone might think that immigrants will be a huge social problems in the near future just like in Europe and the United States. I partly agree with that because most Koreansare not used to living  with other ethnic groups. If the Korean government focuses on tighter border controls, increase the amount of legal immigrants and give a fair chance to undocumented  illegal immigrants to get citizenship,most Koreans would accept and get used to their cultures. It would in turn give a huge momentum to our economy and way of living.