At first, she was stunned to say the least when they first met. He had leapt nearly 30 feet in the air when she fell from the air ship, and landed without even getting hurt. She was even more amazed at his strength. But later on seemed to tone it down when she realized he was just an ordinary mortal with superhuman abilities. She thinks of Riley as a special person, and always gets jealous when girls are around him, becoming a totally different person when she sees him and other girls together, or when it comes to training. Despite her mature stature as a princess and lady, Yue tends to act her true age and become frustrated whenever girls flirt with Riley.
Though in the beginning, Yue saw him more of a younger brother she loved teasing, but also as the means to prove to her people that the Ancients existed and that they could help them. But following the events of the Invasion of the North, Yue falls madly in love with Riley and attempts to keep him away from the other girls who may have affections for him.
She loves him very much and is willing to do anything with and for him. In response, Riley will do anything to protect her, as he loves her just as much as she loves him. Although she felt that there was a huge gap in their relationship as Riley constantly referred to her with formality as "Princess" rather than casually with her actual name as he does with the other girls which greatly hurt Yue. This reached its breaking point when Riley still referred to her so just when attempted to make love to him, from that point Yue became so angry that she began avoiding him for not understanding how she truly feels for him. This began to change when Riley admitted he loves her during the crossing of the Serpent's Pass and again later when they were alone afterwards, when he made a complete confession and called Yue by her name for the first time.
Afterwards, Yue begins to show more confidence in her relationship with Riley, no longer being easily jealous or angered by Riley being close to other girls like she previously does, even suggesting the idea of having them all form a harem for him. She was completely heartbroken Zukai almost killed Riley, and locked herself in her room, crying (which Anna berates her for), but gained a great deal of hope when she found out that he was still alive, as his vitals had slowed down to a crawl to enable him to heal faster. The two of them regularly commit perverted acts together and Riley always assures Yue that she is the most important women in his life, much to her happiness.