+Anima is the name given to humans possessing the animal-like qualities, but the term 'Anima' (without the '+' symbol) is the name given to the animal spirit that the human absorbs.
There are no recorded cases, besides Cooro, of people being born as +Anima, as the conditions for such an event are exceedingly rare. An Anima is absorbed through the sheer will and need to survive. The two common conditions for absorbtion of an Anima are:
- The person is usually between the ages of about 10-18.
- They are having a near-death experience.
For example; Husky became a fish +Anima at a young age of about 10 or so. He could not swim and was pushed into a pond by a jealous rival of his mother. He would have drowned, had he not absorbed an Anima from one of the fish in the pond.
However, some +Anima are genetically created, as an Anima can be obtained through implantation surgery, though, in cases such as Lyra, the process can be unstable. Vice versa, an Anima can be extracted through surgery, in which the marking is removed and the animal-spirit contained.
At the age of maturity, or when they no longer need the Anima, +Anima tend to lose their Anima and become human again, though some adults retain it through puberty, or throughout their entire lives, depending on the circumstances.
The Kim-un-kur are another exception. Due to their strong connection to nature, those of the Kim-un-kur who are +Anima tend to retain it throughout their entire lives, and do not need to be a child to absorb an Anima. They can also, in certain circumstances, give their Anima to their child (though not biologically/genetically).
A marking is obtained when one turns into a +anima. Anima with wings have two marks either on their back or their arms. Fish anima have markings that symbolize gills on his/her neck. Mammal anima markings have only one marking per anima. Most anima keep their anima markings covered, for the marking is a sign of being an outcast. Kim Un kur, however have no need to, for their very proud of their link with nature. Cooro has his showing, like a tatoo. Since Senri is no longer living with the Kim Un kur, he covers the large marking he has on his arm. Some anima have markings that clearly link to their anima soul, like Nana. Although, some have anima markings that are very hard to link to their spirit, such as Cooro.