|Epithet||Princess of the North East|
She has long hair tied on the sides. She wears royal clothes and jewelry.
She likes Sei Kyou and is shown to blush when he is mentioned. She is shown to be very protective of Sei Kyou, as, in the past, she threw stones at Ei Sei because 'he was his enemy'. She is also arrogant as she calls Shou Bun Kun a Moustache guy despite his position in the state. After the death of her beloved husband, she succeeded him as the leader of his faction and gained a large degree of determination to ensure his death wasn't in vain and to defeat the one responsible for setting up his demise, Ryo Fui.
Rui was betrothed to Sei Kyou at a young age. Initially, the two did not get along as she stated he had an unpleasant face while he was angered by her insolence. On the other hand, he was secretly entranced by her and eventually developed feelings for her. Meanwhile, she was loyal enough that she would throw rocks at his perceived enemy, Ei Sei.
She was first shown blushing when a messenger notified her that Sei Kyou was coming with his carriage. She was very surprised when she sees Ei Sei instead of Sei Kyou. She greeted them and mentioned she overheard Shou Bun Kun stating his suspicions of Sei Kyou. In response, she declared that her husband was dedicating everything to the prosperity and safety of the kingdom, and it would be unthinkable for Seikyou to turn on Sei as even if he still wanted to, both factions still have to worry about Ryo Fui.
Shortly afterward, she returned to Tonryuu for her grandmother's eightieth birthday taking a gift from Seikyou with her. When the Zhao army appeared at the gates, she let Ho Kaku lead her away from where he imprisoned her.
She sat in her prison until Seikyou arrived to rescue her with a few other troops, and they ran away through the hidden corridors of Tonryuu. She left Seikyou behind to hold off the troops and ran through the corridor to safety. She emerged in front of the Hi Shin Unit and begged them to help Seikyou. Though they ran as fast as they could, the didn't reach him in time. She listened to Seikyou's last command to Shin, then embraced him as Seikyou died in her arms.
- She seems to have a paranormal ability of sensing and physically seeing spirits, as seen throughout many moments durring Ei Sei's coronation.