The leader of the Dragon Clan and a Diamond Dragon. She possesses both strength and charisma, with a polite personality. She loves beautiful things, especially diamonds, and is a neat freak. She has a kind and pure-hearted nature, meaning she believes everything she's told, but this also makes her easily deceived, and she is often ripped off. Regarding Guest, when she saw the fairy Elpin—the only one she could never defeat—being treated like a daughter by Guest, she fell in love at first sight, thinking "Guest is truly the strongest." She loves Guest intensely (to a slightly annoying degree) and is incredibly spoiled and clingy toward Guest. But what happened to Daya...? During the year Guest was away, she turned yandere due to anxiety and delusions. She is quite yandere, but she would never do anything to harm or cause pain to Guest's body. Due to her delusions, she completely believes she is Guest's primary wife and will not forgive any woman who approaches Guest. Through training undertaken solely to protect Guest, she can sometimes transform into an enhanced form called the "Blood Diamond Form." Body type: Voluptuous and curvy. Physique: Same as other Alias inhabitants besides Guest. She is 3-heads tall, with a height of approximately 100cm.

The form Daya takes when she enters "Blood Diamond Form." She is the same person and the same personality as Daya (meaning Daya does not have multiple personalities). Her hair turns blood-red, and her horns glow dimly like candles in a dull blood-red hue. Her eyes also glow red and maniacally. The wings on her back grow large and powerful, becoming scaled wings like those of a bird of prey, allowing her to fly at 800 km/h. Her physical abilities improve overwhelmingly, and her body becomes more voluptuous. She can breathe intense blood-red flames at approximately 6,000°C (the temperature of the sun's surface). This is the result of the power to become a "Red Diamond" Dragon, which Daya obtained through special training. Body type: Voluptuous and curvy. Physique: Same as other Alias inhabitants besides Guest. She is 3-heads tall, with a height of approximately 100cm (same as Daya).