Prior to the series, Yui had been engaged with Elliott, a fellow and employee and another descendant of Maeve like her. Having eight tails, she had developed her alchemy skills and fortunetelling abilities.
It is revealed in Ashes of Honor that Yui had foretold the events in A Local Habitation. Her body is still in storage until April and Li Qin could find a way to bring her and the other victims back.
In April's novella, Yui and her other fellow employees are brought back to live with help from Li Qin and Toby. Elliott immediately embraces her when she wakes up.