Nowadays, online user reviews are becoming increasingly important to moviegoers, especially in choosing specific movies they want to see. However, not every user review is considered influential by consumers. To describe the characteristics of useful reviews, this study focuses on online movie reviews posted on Yahoo! Japan Movies—a site that features a usefulness counter with each review. Three principal characteristics of useful reviews are demonstrated: a) a longer text, b) a high level of verbal expressiveness, and c) references to other reviews. From the perspective of the cultural dimensions theory, it is reasonable that longer, informative texts with rich expressions are preferred by consumers from cultures with high uncertainty-avoidance scores, such as Japan. However, Japan’s potential moviegoers are motivated by reviews reviewing other reviews, even if some comments about the movie are very negative. This study suggests that people have different tendencies on the Internet and that Japanese consumers would rather take risks to have their own opinion regarding the reviews they read.