There is a ring, a golden ring very special. This ring, called the "Ring of pleasant soul corruption" only applies to girls of 14-18 years, or on male children.
1) In the first case, his task is to bring out the bad personality of a girl: can be gentle, romantic, correct what she wants, but once worn the ring will become psychologically obsessed with sex, selfish and bad, without any sense of responsibility. The process of change is very slow.
2) In the second case the child has a rapid transformation becoming a fourteen year old girl, once turned slowly begin the same psychological changes in the first case, although certainly the subject, being a child, one will notice much before about the change.
In both cases, the person will love his new change and hate your condition without the ring. The most frightening peculiarity, however, is this: when worn, the ring can be removed only once the subject has been transformed completely. In other words the person wearing the ring can no longer prevent the change and will last forever.
The people who now can find the ring are two:
1) Ashley, a girl of 17 years, beloved by all. She always gets high marks, like his parents, he has a strong sense of responsibility is very romantic and has never had sex.
2) Tod, an 8 year old boy who loves to play and loves superheroes and cartoons. Always lively and sweet with everybody.
(I had this in mind but unfortunately I can never finish it for various reasons, so I leave to you the continuation of the stories and the description of the transformation, in order to see your fantasies, as you prefer to best tell their psychological changes, good fun!)