Yin, whose full name is Yin Hoshimi (星見 銀), is one of the main characters in the anime series Darker than Black. She is a Doll, a type of emotionless medium with the ability to observe water molecules and track people. Yin acts as the team's observer, supporting Hei and the others with her surveillance skills. Though initially emotionless, Yin gradually develops human feelings, making her a central figure in the story's exploration of identity and humanity. Her quiet presence and hidden depths make her an intriguing character.