Unagi Tanaka is a minor character from the anime and visual novel series 'Popotan.' She is a friend and classmate of Ai and Mai, known for her quirky and lively personality. Unagi often provides comic relief in the series, and her name, which means 'eel' in Japanese, is a running joke among the characters. Though not a main character, Unagi plays an important role in supporting the leads and adding a touch of humor and warmth to the story's school life segments.