Ever watched a video online and been bombarded by a flurry of comments flying across the screen? That’s Danmaku, a popular feature in East Asian video platforms. While it adds a lively social layer to the viewing experience, it can also quickly become a breeding ground for toxic comments and spam. A new approach, rooted in AI, aims to change that, proactively fostering a more positive online community. Researchers have developed 'DanModCap,' a tool that uses 'Impact Captions' to subtly guide viewer behavior and encourage positive interactions. Inspired by commentary techniques from East Asian variety shows, these captions analyze real-time comments using AI and inject witty, humorous, or explanatory messages back into the stream. These aren't just clever quips; they're carefully designed to resonate emotionally and cognitively with viewers, encouraging self-reflection and positive engagement. For example, if a comment attacks a player in an esports video, an Impact Caption might humorously counter, reminding viewers to keep things respectful. If the comments veer off-topic, an Impact Caption can gently redirect the discussion back to the video itself. A user study of DanModCap found that these Impact Captions led to increased self-awareness in how people comment. Seeing humorous or thoughtful responses to negative or off-topic remarks prompted many to reconsider their own contributions, leading to a more positive atmosphere overall. Though promising, some limitations exist. For instance, accurately interpreting the nuances of language and culture in real-time remains a challenge. Additionally, future research needs to ensure that these AI-generated responses don’t create echo chambers or amplify existing biases. The next step is to refine the emotional intelligence of these AI moderators and carefully navigate these challenges for broader, cross-cultural application. The potential to shape more welcoming online communities is huge and Impact Captions could be a valuable addition to the content moderator’s toolkit.