Rei has been well received by critics and in reviews. She has maintained a high ranking in every popularity poll of the series and has also appeared in polls to decide the most popular anime characters in Japan. Reviewers have praised Rei's mysterious aura, and her role in the story. Merchandising based on her has also been released, particularly action figures, which became popular. Critics attributed her success to a series of moe traits that proved popular with anime fans, influencing the creation of subsequent female anime characters.