[4] After retirement from the university, he was appointed to the director of National Diet Library in 2007 and held the position until 2012.

[10] Nagao was one of the first scientists who developed practical machine translation (MT) systems.

Between 1982 and 1986, he led the Mu project which aimed at translations for technical papers and became the first successful MT system between English and Japanese.

[2] In addition, example-based machine translation, an important approach for MT, is the method proposed by him in the early 1980s.

[15] Another NLP resource developed under his laboratory is Juman,[16] a Japanese morphological parser and the first system which merged word segmentation and morphological analysis for languages which do not have explicit word boundaries (such as Japanese or Chinese).