Sinful World is a tale involving numerous characters. A married woman, a female college student, an employed man, a woman with a netorare fetish, a man who enjoys seducing other men's partners, a son with his mother, a daughter with her father, cousins, twins, siblings, stepson with stepmother, stepfather with stepdaughter, as well as stepdaughter with stepmother, or daughter with mother.

Numerous stories exist, with the first being about a stepson and his stepmother and one more girl.