Succubus Syndrome is:
A new syndrome that occurs in adolescent girls.
It is most commonly seen in girls who harbor intense feelings of love,
but are unable to convey their feelings due to their personalities.

It often occurs during the period in which the girl's body grows lewdly.
It is extremely rare for it to occur in fully mature woman.

After coming down with succubus syndrome,
a girl's hidden feelings of love turn into unstoppable sexual urges, and both her personality and physical body are greatly affected.
Physically, her eyes glow red, and she grows a demon-like tail and wings.
Mentally, she becomes very loose with sex, and typically begs men for their sperm.

To treat succubus syndrome, it is said that
a girl must have lots of sex with a boy until she's satisfied, or fulfill her feelings of love.(Text: English / Voice: Japanese)