<p>The rise of social media has led to new studies on collective attention in specific events such as elections and sports. In the context of collective attention, phenomena such as rapid increases in the number of posts and the sentiment of the content have been extensively studied. However, microscopic details, like who is participating and the specific words used in posts, are not yet fully understood. Therefore, this study proposes a new indicator to quantify the state where a broad range of participants exhibit their narrow attention. We tested this indicator using over 10 million tweets related to Japanese professional baseball teams, where many participants exhibit their attention towards the team they support. We confirmed that collective attention occurs in both positive events, such as championships, and negative events, such as player injuries. This did not necessarily correspond to the simple post volume. Additionally, an analysis distinguishing between own-team fans and fans of other teams revealed significant collective attention occurred when involving fans of other teams. By employing the microscopic perspective defined in this study, which considers localized attention with a broad range of participants, we elucidate the mechanisms of collective attention and provide insights into the origins of collective attention.</p>