There are two major culture points in the Japanese language: social verticality (tate-shakai) and in-group/out-group distinction (uchi-to soto). These culture points are not only important in Japanese society, and represent unfamiliar concepts for most English native speakers. A key factor in successfully learning the language is to understand the culture points and know how to utilize them in actual language use from the beginning stage. In this dissertation, the six most popular textbooks used by college-level Japanese programs in the United States were selected based upon two surveys. This dissertation examines how each textbook deals with the two culture points from different angles such as topics, functions, situations, grammar points, and modality of presentation. Every textbook has both strong and weak points in terms of incorporating the teaching of the culture points. Teachers of Japanese language and culture should know how well their textbooks incorporate the culture points in order to improve their students' communicative competence.