After

An After (アフター, Afutā) is the spirit of a twin who has been absorbed by the other twin. They form a symbiotic relationship with their Double.

Description
Afters are born through the unique phenomenon of a twin absorbing the other twin in the uterus while also conjoining with them spiritually. Another condition for the event to occur is the mother making contact with a or other spiritual entities. Afters grow and develop as their Double does and are often mistaken for imaginary friends by the Double's parents in their childhood, their anger usually resulting in outbursts that gets their twin in trouble. An understanding must be met between the Double and After for them to properly coexist. Once a solid bond is made, however, an After's assistance is extremely helpful to the Double.