The eroge company Nitro has a division that produces exclusively BL games, known as Nitro CHi RAL.
Like other pornographic media in Japan, erotic scenes feature censorship of genitalia, only becoming uncensored if the game is licensed and released outside Japan, unless produced illegally by doujin (usually with a construction kit like NScripter or RPG Maker).
Although many eroge still market themselves primarily on sex, eroge that focus on story are now a major established part of Japanese otaku culture.
Oftentimes, voice actors who have voiced for eroge have been credited under a pseudonym.
NEC was behind its competitors in terms of hardware (with only 16 colors and no sound support) and needed a way to regain control of the market. The first commercial erotic computer game, Night Life, was released by Koei in 1982.
Early eroge usually had simple stories, some even involving anal, which often led to widespread condemnation from the Japanese media.