(Posts #4-9, translation of http://www.kyo-kan.net/column/eroge/eroge1.html
, ©Todome Satoshi)
Eroge / Ero-games
Welcome to Japanese word history 101.
The actual original dictionary definition for "hentai" is "someone who acts strangely." Technically, by the old terminology, oh let's say...someone who wore hats on their feet and shoes on their head would be coined as "being a hentai."
Flash foward to the 1960s. The world was going through a counterculture revolution - anti-war, sexual openness, etc. Japan was no exception. Sex, started becoming more open, as the young postwar generation began to rebel against the older prewar generation. By means of media and slang term, someone started using "ecchi" as a replacement for sex. The actual Japanese word for "sexual intercourse" is "seikoui." But then again, who the heck is going to use "Let's have sexual intercourse" when a shorter, blunter version "Let's fuck" is available? Same thing in Japan, rather than saying "Anata to seikoui shitai" (I want to have sexual intercourse with you), a shorter, blunter saying "Ecchi shiyouze" (Let's fuck) is available. By now, I take it that most people here knows that the word "ecchi" stems from Japanese pronounciation for the English letter "H" - the first letter in the romanized word for "hentai."
Due to this use of "ecchi/hentai" as a replacement for "sex" in the 1960s, the word stuck into the Japanese that "ecchi" (or in Japanese usage, we just write the English alphabet "H" for sex) meant sex (or at least sexual content).
By 1980s and early 1990s, we started seeing porno anime and porno games in Japan. In Japan, these were referred to simply as "H-anime" (ecchi-anime) and "H-games" (ecchi-games). For some reason, in the overseas, you guys understood that "ecchi" (H) meant the first letter for the word "hentai," so you began to refer to these animes and games as "hentai anime" and "hentai games." (While in Japan, we never used those...we just used the letter "H" only). And as these games became more and more hardcore with rape, bondage, and tentacles, you guys began to refer to these pictures as being "hentai," whereas in Japan, we just referred to them as being "H-scenes" (ecchi-scenes).
But somewhere around the mid 1990s, (some say it began with Leaf's "Shizuku" and "Kizuato," others point a little later to "To Heart") these games gradually began to distance itself from hardcore pornography to story-centric love-simulation games (many point to the immense success of Konami's "Tokimeki Memorial" that started this whole love-sim phenomena). When one company made a huge success in story-based games, many other companies followed.
Suddenly, these games weren't just about sex anymore. They actually began to put real effort into actually great stories. And as more and more of these games began to hit the shelves, more and more of us began to ponder: these aren't just "ecchi games" (sex-only games), these are rather "games with actually great stories that just happen to have sex scenes in them."
Hence, a new terminology began to appear (by word of mouth, by mass media, etc.) and gradually the terminology "H-anime/H-games" (ecchi-anime/ecchi-games) began to disappear in replacement of "ero-anime/ero-games." For some reason, at least in Japanese minds, the English word "erotic" is less objective than the blunt word "sex." So, rather than the blunt "just sex games" (sex = "ecchi") we began to use the more toned down version of "games with erotic scenes in them (erotic = shortened to "ero" in Japanese)."
By the late 1990s, the word "hentai/ecchi" was dead. It still is used for the action verb "let's fuck" (ecchi shiyouze) in everyday language, but the usage of the word "hentai/ecchi" as an adjective had disappeared. It has been replaced by the term "ero."
So, from now on, the word "hentai anime," "hentai games," "hentai pictures," and "hentai scenes" are all words that no one in Japan uses anymore. Start using the word "ero-anime," "ero-games," "ero-pictures," and "ero-scenes (actually the actual word in Japanese for "ero-pictures" is "ero-gazou," but that's going too extreme).