This group may include any game with significant amounts of nudity and/or explicit sex scenes that was either made in Japan or clearly imitates the Japanese way of making such games.
Hentai (Japanese 変態, "perverse"; can also be understood as "shape-changing" or "weirdly shaped") is the term commonly used in the West for such games.
Bishōjo games are similar to Choose Your Own Adventure books in the way of narrative.
Where the game tells a story, but the player may make choices to change how the story flows. While in the Western industries, those games can be considered as visual novel, this Japanese market for Bishōjo games have its own growth unrelated to the Western world.
All of these are closely related and many games would fall into more than one category.
However, which word you choose places the emphasis on different aspects of the game.
Bishōjo games began to appear in Japan in the beginning days of personal computers.
The first bishōjo game commercialized in Japan appeared in 1982 as Night Life by Koei.
We would recommend you to try out New Love Plus that was released in 2014. In New Love Plus , you will be playing the role of a new transfer student and meet 3 girls named Manaka, Rinko, and Nene.
They form a sizeable fraction of the Japanese market: the most popular have sold over a million copies, and they make up the majority of offline PC games in Japan.
Nevertheless, only a few titles of this sort have been translated or commercialized outside of East Asia.
In Japan, the preferred term is Eroge (エロゲ, short for "erotic game").
Bishōjo (美少女, "pretty girl"; also referred to as Gal Game) is a rather vague designation, often used to describe any game in which the player character interacts with attractive anime-style girls, regardless of the adult content.
Even the most introverted of them all, who enjoy being alone most of the time, may feel lonely at times.