The biggest difficulty for Japanese companies is their unconscious "Japanization" of their [foreign] workforce. According to a survey conducted by job information provider Disco, while most Japanese companies say they need excellent human resources regardless of nationality, they tend to require foreign workers to have a high level of Japanese language proficiency and to conform to the country's working culture. Both can be points of tension with foreign staff. Many international students and workers come to Japan unaware that a high level of Japanese language ability is often required to work here. They can be rejected for jobs simply because they lack Japanese fluency, regardless of their ability and experience. Many students have told me they thought they could work in an English-language environment in Japan because of the presence of so many multinational companies here. There is also often a mismatch in working styles. This is because Japanese companies are accustomed to having staff stay with them for their whole work life. But many talented foreign employees expect to be promoted or to change jobs for new experiences as often as every three to five years.