NEET is a government acronym for people currently "not in education, employment, or training". It was first used in the United Kingdom but its use has spread to other countries, including Japan, China, and South Korea. People under the designation are called NEETs (or Neets).
Image Via: NFKJapanese NEETs include many who have rejected the accepted social model of adulthood. They do not seek full-time employment after graduation, or further training to obtain marketable job skills through the governmental work schemes. They might be reacting against the traditional career path of the salaryman.