Faafa is Ren's sister, even though they share the same body. Faafa maintains a happy, cheerful attitude wherever she goes. She quickly becomes attached to those who show her kindness, as seen with Ai. However, she can also be emotionally unstable at times. Faafa doesn't mind using her powers to get what she wants.
In contrast, Ren is brash, rude, and somewhat of a punk. He enjoys picking fights with others, regardless of their status. Despite this, he has great respect for Zero and eventually comes to like Ai. Ren is driven to protect Aura users from attacks by human extremists. Like his sister, he also doesn't mind using his powers whenever he likes.
