This study develops a method for improving creativity by changing the facial appearance of people during video conferences. We focus on enhancing creativity during human interactions, especially cooperative work situations such as video conferences. Psychological studies have revealed that the facial appearance of people can affect creativity, i.e., "emotion can affect creativity" and "the appearance of others can affect the emotions." Based on the knowledge, we hypothesized that the media technology which modifies the facial appearance of people appropriately can enhance our creativity during cooperative work. Therefore, we develop a method to affect creativity by changing the facial appearance in real-time, such as facial expressions and facial resemblance. We test the effectiveness of this method by building a system for collaborative video conferences. The user study show that the proposed method could enhance creativity.