Cogenitor

Plot:

Enterprise encounters a hyper-giant, the first to be studied by humans. While there, they make first contact with the Vissians, a technologically sophisticated race with three genders. While making quick friends and eagerly learning about the advanced technology, Trip gets curious about the Vissians third gender, known as the Cogenitor, who is crucial in the Vissian reproductive process. While intellectually equal to males and females, the Cogentior are not granted the same liberties, such as freedom of travel, education, or even names. Against the wishes of the Vissians, Trip befriends the Cogenitor and encourages it to defy it's cultural boundaries, teaches it to read and shares Earth's movies with it. The Vissians are made aware of Trip's efforts and are insulted.