Screenshot of the hentai bishojo game "Kango Shicyauzo."also translit. bishōjo or bishoujo; pl. n. bishojo (never “bishojos”)
1. n. Japanese slang 美少女 “beautiful young girl”; refers to attractive girls below college age, esp. as depicted in anime and manga; related to biyōjo 美幼女 “pre-adolescent girl.” See also moe.
2. bishojo game, a Japanese genre of video and computer game marketed to straight adolescent boys, centered around social interactions with bishojo; many are pornographic hentai games, but the majority feature romantic storylines; also gal game or galge (ギャルゲーム gyaru gēmu); from Japanese 美少女ゲーム bishōjo gēmu, bishojo + English game “pretty girl game.” See also dating sim.

Addendum: Bishojo games have fans in the west, but they usually do not have published English-language ports. This is because the games are usually considered sexist and/or pornographic. Female characters in bishojo games may be presented as submissive to males to an extent that offends some Westerners; the games also often feature highly-sexualized depictions of teenage children.