Yui Yagi is a fictional character from the anime series Jantama. Known for her cheerful and energetic personality, Yui often serves as a source of motivation and encouragement for her friends. Her skills in strategic thinking and quick decision-making make her a formidable player in the mahjong games that the series revolves around. Despite her seemingly carefree demeanor, Yui is deeply competitive and strives to improve her game, often surprising opponents with her unexpected plays. Her role in the series highlights themes of friendship, perseverance, and the joy of playing mahjong.