If the foreign students have graduated from a vocational school and obtained the "Diploma" or "Advanced Diploma", they are eligible for acquiring a working visa ("Instructor", "Engineer" or "Specialist in Humanities/International Services") when they find employment in Japan.
However, the immigration services bureau will carefully examine the relevance between their major at a vocational school and expected duties at a company compared to university graduates for students with the "Diploma".
If the students have graduated from university overseas and earned the "Diploma" in Japan, they only need to prove the relevance between expected duties and either of their university degree or Diploma.