HistoryEditTsui-Ling is the girl Kazuma could not protect. She was sacrificed by the head member of the Armagest Erwin Leszaar to summon a demon. Rhodes used a spell to gather her remaining essence into a being called Lapis. Before her sacrifice, she and Kazuma worked in a restaurant, and were in love. According to Lapis in the last episode, her last thoughts were that she wished Kazuma was dead. Whether this is true or lies meant to cause Kazuma pain is unknown (Kazuma notes that she may have felt this out of spite towards his inability to save her). As Lapis, she is trained in anti-mage fighting .
She worked at a shop and with the arrival of Kazuma, began to fall in love. She asks him if he still wants power, so he could return to the Kannagi family someday, he tells her she is an idiot and tells her that everything he ever dreamed of was with him right now, as long as she was with him. She asked him on a night of a full moon if he would protect her forever. Kazuma promised he would always be with her like the wind on that night and the two share a kiss. Despite everything, she was chosen to revive a youma and in front of Kazuma's eyes, was killed.
Kazuma tells Tsui-Ling in his mind at the end of Episode 22 if it was alright that he found someone else that he wanted to be with, but she would always have a place in his heart.
Kazuma Yagami : She was in love with him until she was sacrificed to summon a demon.