This study examines language in conjunction with co-speech gesture awareness and use in relation to second language development, and as linked to identity-in-the-making for four Chinese international graduate students attending an American university in the U.S. Data collection took place at two different times: after three months of initial exposure and then again three years later. Participants were interviewed about their language and gesture awareness and use in the L1 and L2, and in relation to possible changes in identity over time. Additionally, participants were video-recorded while retelling a story that included motion events in their L1 and L2 at both times of data collection for possible changes in thinking-for-speaking. Findings are related to four areas: speech-gesture synchrony; language, gesture, culture and emotions; gesture awareness and use; and bonding with others. Overall, this study offers a window onto the role of co-speech gesture in relation to second language development as found in the contexts of naturalistic exposure, where agency plays a significant role in identity development, differing for individuals in accordance with how a person experiences an event or environment (perezhivanie).