Night Life

Night Life (ナイトライフ) is an erotic simulation game developed by Koei early on as part of its Strawberry Porno series. Considered the predecessor of the bishōjo gaming genre, it was the first of its kind to be commercially released. The game was also touted as an educational tool by the company to help couples enhance their sex life with one another.

Gameplay
Players are given a limited set of options to tinker with before initiating the virtual intercourse phase of the game. These options range from determining the date of a woman's period (thus serving as a rhythm method calculator) to deciding on which sexual positions to include and how much time should be allotted for each one.

The resulting sexual intercourse is then displayed on the screen with a timer via "Let's Fuck!!" option which outlines the graphics in white. A sex diary option is also available for players to record their gameplay experiences.