Yagi Yui is a genius with an IQ of 180, but people keep their distance from her because she cannot interpret their emotions. Still, she longs to understand others and to be understood. On a chance visit, she came to the Mahjong Soul Shrine, and she started to change. Other than coffee and snacks, being her favourite beverage and food, Yui really has a poor sense of taste.
(Source: MahjongSoul Wiki)