Hai Yi is a fictional character within the world of Vocaloid, specifically a part of the Hatsune Miku universe. She is one of the Chinese Vocaloid characters developed by Shanghai HENIAN. Hai Yi is depicted as a mermaid with a calm and mysterious aura. Her vocals are designed to bring a fresh and ethereal quality to songs. In the series, she adds a unique, mystical element, often associated with themes of the ocean and fantasy, enhancing the diverse musical landscape of the Vocaloid series.