Immoral Emotion

Immoral Emotion is a Japanese erotic visual novel about forbidden familial relationships.

The player controls one of two protagonists. The first protagonist is Naoki Aihara, a boy who starts to get curious about sex after seeing a female family member naked. The second protagonist is Motohisa Aihara, a man who married his wife, Manami, a little over a year ago, but is somewhat unsatisfied in the marriage because her sexual preferences are very vanilla compared to his. The other members of the Aihara family are Manami's sister Sayaka, who has been living away from her workaholic husband for over ten years, and Yuuka, Manami and Sayaka's young sister. The player can choose their protagonist as well as which heroine they would like to pursue (Sayaka, Manami, or Yuuka) from a selection screen, with the ending experienced varying depending on their choices.