Have you ever desired something or someone that didn't belong to you?
Ashton Emma was living her life with any worries until she met the person that changed her calm life into a very wrongful one, and that someone is her sister Rosalie's boyfriend, Allen Ryan.
A conflict between sisters and between Emma's own feelings will occur, involving also their childhood friend Harris Ray.
Everyone knows Sin has a particular taste because it's part of us humans to incline ourselves towards something forbidden, and Emma will get addicted to it, even though her mind will keep telling her 'It's wrong'.