In a world filled with magic and color, a young girl named Yumi embarks on an unforgettable adventure when she encounters Unico, a small unicorn with the power to bring happiness to those around him. However, his joy attracts the attention of an evil god who fears that his light will overshadow the darkness he reigns over. Determined to eliminate Unico, the god banishes him to a distant island, where the inhabitants, weary of their sadness, have lost hope in goodness.
Yumi, with her pure heart and desire to help, decides to follow Unico and rescue him. On her journey, she meets various magical characters, from a brave mouse to a strange yet wise cat, who help her face the challenges that stand in her way. As she ventures deeper into the island, Yumi discovers that happiness does not solely depend on a unicorn, but on the strength of friendship and love that can blossom in the hearts of all.
While the evil god tries to separate Yumi and Unico, the young girl must unlock her inner courage and unite with her new friends to free Unico. In an exciting climax, the magic of love and friendship will shine brightly, showcasing the power that hope has even in the darkest moments. The movie is a charming blend of laughter, tears, and lessons about the importance of never giving up.