This study analyzed the uses and functions of speech levels and speech level shifts in natural conversations between two unacquainted males. Similarities and differences between Japanese and Korean languages have been investigated. For the Japanese language, speech levels do not clearly reflect the hierarchical relationships based on the interlocutors’ age by utilizing “non-marked utterance (NM)”. This finding implies that modern Japanese people tend to avoid the use of honorifics which clearly indicates the hierarchical relationships between speakers at the sentence level. On the other hand, speech level shifts reflect hierarchical relationships between speakers, which means that Japanese seem to conform to normative language use at the discourse level. For the Korean language, both speech levels and speech level shifts clearly reflect the hierarchical relationships based on the interlocutors’ age. This result suggests that Korean have a strong tendency to preserve the normative honorific usage of polite forms according to age difference both at the sentence level and at the discourse level. These results suggest that speech levels, considered to be socio-pragmatically obligatory, have a strategic-use aspect for both languages, including the use of “non-marked utterances” and that of downshifts. It was also discovered that Japanese tend to use speech levels more strategically than Korean. Consequently, Japanese uses honorifics strategically in order to evade hierarchical relationships based on age, whereas Koreans tend to conform to social norms that derive from tenets of Confucianism, a philosophy emphasizing politeness toward older people; such practice encourages younger people to use polite forms to their elders.