Queen Mother

太后 ( たいこう

The Queen Mother is King Ei Sei's mother and the leader of the Royal Harem faction.
In the past, she was known as the "Jewel of Kantan" for her stunning beauty. At that time, she was Ryo Fui's fiancée and deeply in love with him. Ryo Fui gave her to Sei's father to become one of his many women, aiming to gain from this arrangement in the future.
She became a political hostage alongside Sei in the State of Zhao, where she gave birth to him. During that time, she and Sei suffered tremendous hardship under the people of Zhao, and because of that, she grew to hate Sei and even attempted to kill him at one point.
After Sei successfully escaped from Zhao at the age of eight and became the king of Qin, the Queen Mother was brought to the capital as well and became the head of the Royal Harem.