The Japanese interjection un
has various phonetic features that indicate different meanings and functions. As a preliminary stage toward developing a precise analysis, I observed the use of un
in a television drama in order to understand what kind of functionality and phonetic features it has in natural speech. Consequently, I determined three main categories of meaning for un
: 1. speaker indicates the result of the processed information; 2. speaker indicates output information is being processed; and 3. non-processing related. The first category has five subcategories: affirmation (falling pitch), non-comprehension (sharply rising pitch), negation (falling-rising pitch), speaker indicates input of novel information (longer duration with gently rising pitch), and speaker indicates neutrality (flat pitch). The second category adopts longer duration and flat pitch, and the third one adopts flat pitch. In this paper, I will discuss these three categories and indicate their implication for future research.