Junmian Wang, Guojun Liao
This study examines digital emotional resonance in cross-cultural sports livestreaming through the analytical chain of host narrative-audience affective response-subsequent visible participation. Using the Chinese livestream of the Hakone Ekiden as an observational single-case study, we analyzed 97,878 publicly available interaction records collected across two race days. Sentiment scores for both audience comments and host commentary were generated using a fine-tuned BERT-base-Chinese model, and the main statistical analyses were conducted with 20-s time windows. Lagged correlation and impulse-response analyses were used to trace the temporal relationship between host and audience emotions; event-window models compared the differential roles of A1 technical commentary and A2 cultural-translation narrative; user-level grouping was used to examine platform-visible hierarchy; and forward-looking gifting-window models tested whether emotional alignment extended into subsequent gifting behavior. The results show that the pooled sample does not support stable zero-lag synchrony. Instead, the study provides weak and observational evidence of short-lag coupling, with the positive association appearing mainly when host emotion leads by approximately 40 s. A2 narrative does not consistently shorten audience response latency, but on the second race day it is associated with higher emotional maintenance during the 20-60 s after the event. Higher-level users show clearer same-window coupling and a higher probability of gift entry, although this result should be interpreted cautiously because user level may also reflect prior platform activity, platform tenure, and consumption tendency. Tighter emotional alignment between the host and the audience is associated with higher gift quantity and gift value in the subsequent time window. Overall, digital emotional resonance in this case is better understood as a conditional social process rather than as continuous, strong, and generalizable immediate synchrony.