Robin is a teenage female with shoulder length hair tied in plaits. She has thick eyebrows and freckles on her face, something she takes note of, and believes Canary and Gabrielle to be much more beautiful than her.
As a seraph, her markings are orange in color.
Robin has a very gentle and motherly personality and is often seen taking care of her teammates, such as Parrot who she is especially close to. When around Arthur, her disposition becomes rather shy and believes herself to be unworthy of his affections.
She has a crush on Arthur C Phoenix that is reciprocated.
After the genocide on Arthur's group of seraphs, she becomes colder and more distant. She takes up Arthur's dream of freeing all the seraphs, even if it requires destroying the human race in order to create a world for seraphs.
Robin was among the seraphs Arthur freed from the Arizona farm. She greets him enthusiastically, only to be interrupted by Canary. She accompanied him and the other seraphs as they traveled around the continent to freeing the other seraphs from their farms, and assisted Arthur in his attempt to contact every other seraph across the world. Along the way, her affections for him continued to grow and they occasionally spent intimate time with each other.
Upon reaching a farm with only one seraph held inside, Arthur rushed in to help release him while she stood on standby in the air above. However, the situation turned out to be a trap when the farm exploded with Arthur still inside, and she could only watch as her friends were killed one by one, either by being shot or by being poisoned by gas. As she cried out for Arthur, she was shot and thought to be dead, but managed to survive and awaken.