Japanese im/politeness attitudes are conveyed by audiovisual prosody in tandem with lexical markers. This chapter reports on two experiments about the acquisition by Japanese elementary school children of prosodic codes and social categories. The first experiment studied the perceived degree of politeness and its social use, and the second, the perceived similarity between the expressivities conveyed in pairs of expressions. An analysis of the audiovisual performances showed the types of changes in pitch and range in line with symbolic frequency and effort codes. The perceptual results showed that children learn to use and recognize im/polite expressions in a socially adequate fashion between 6 to 10 years old, thus showing an underlying growing cultural coherence gained with age.