The Japanese The Japanese Don't KnowThe Japanese The Japanese Don't Know.

The Japanese That The Japanese Don't Know (Japanese: 日本人の知らない日本語, Hepburn: Nihonjin no Shiranai Nihongo) is a manga and television series about a Japanese teacher and her students written by Takayuki Tomita and Umino Nagiko. It discusses the background of Japanese words and speech. There have been four paperback volumes as of August, 2013.