Cooro is a crow +Anima and the main character of the series. His +Anima marking is located on each of his arms below the shoulder and is a spiral with five feather shaped markings decreasing in size around part of the swirl.
He first appeared when he was captured by a greedy circus ringer and marketed as the "Dark Angel". The circus is where Cooro meets Husky, who was captured before him. Cooro was not only known as a dark angel there- throughout the series people mistake him for a messenger of death or a sign of bad luck. He also has the unique ability to sense the presence of other +Anima.
Cooro has blackish-brown eyes and black hair  that comes down his back in a short braided rat's tail with a small crimson ribbon tied on. To protect his eyes from strong winds, a set of yellow leather aviator goggles adorned with two colourful decorative feathers lie on Cooro's head. On his arms, he wears a pair of crimson fingerless shoulder length gloves with a matching sleeveless undershirt. On top, there is a high collar backless yellow tunic that is kept on by a brown belt strapped around his waist. He has loose denim pants that end just below his knees and a pair of yellow gum boots with crimson socks. He obtained a hatchet from a blacksmith named Harden in volume 3, which he uses to chop wood. His black crow wings grow on his back, like most bird +Anima wings.
Cooro is a skilled liar and rather mischievous at times often involving himself in the problems of many others, but still very naïve and random. He is also very gluttonous and his favourite food is apples (which he eats without second thought at every opportunity). But frankly, he eats anything edible. Although most +Anima try to hide their powers, Cooro loves and even shows off his gift regularly, likely because he had them since he was born and feels no shame because of his +Anima. He tends to honour people's decisions, to the point that if people tell him to go away or to leave them alone, he will do exactly that and won't pursue them, although rejection often causes him to go into a sulking form with his wings folded around him.
He was found in a church as a baby, already with his crow wings. Cooro is the only person mentioned in the series who was proven to be born a +Anima. In the town of Lilt, where he was born, Cooro's mother died while still pregnant with him. The custom in Lilt is to have the body of a deceased eaten by the crows and Cooro, somehow still alive inside his mother, broke free of her body and drew in a crow Anima out of longing to chase after her spirit.
Cooro was raised at the church, then taken to the research facility in Astar. Here, he befriended Fly, one of the researchers. Fly asked Cooro if he could take his Anima through 'Anima Removal Surgery' when he was older, and Cooro, who was very young and didn't understand what he was promising, said yes. Fly sent Cooro out to find more +Anima to preform the surgery on, but Cooro forgot the mission on purpose, only remembering that he was looking for other +Anima. The reason for this is he preferred to keep traveling with the others.
When he eventually returned to Astar, Cooro remembered his promise and agreed to let Fly take his Anima, much to the dismay of his friends who refused to go through the surgery. Although the transfer was successful, Cooro felt lost afterwards and wandered back to the place in Lilt where he'd become a +Anima. He experienced a deep longing for something in his heart that he couldn't obtain and grew his wings back. He made to fly away, but his friends came to stop him, and his void was filled with their friendship. It is certain that his Anima reverted from Fly, back to him as Senri seems to be able to tell the difference.
Original Short StoryEditCooro is much more violent and his behavior is more wild in the original short story. He also has a bird tail when using his +Anima, including long feathers that grow out of his arms.
Cooro has leather aviator goggles with two colourful decoration feathers. In his pouch made of fur and leather are emergency rations and acorns, a stone knife, and coins. He also has a hatchet on his belt with his pouch which he got from the blacksmith Harden.