Voice acting in Japan has far greater prominence than in most other countries. Japan's large animation industry produces 60% of the animated series in the world; as a result Japanese voice actors, or seiyū (声優), are able to achieve fame on a national and international level.
Besides acting as narrators and actors in radio plays, and performing voice-overs for non-Japanese movies and television programs, the seiyū are extensively employed as character actors in anime and video games. Popular seiyū, especially female ones such as Kikuko Inoue, Megumi Hayashibara, Aya Hirano, Aya Hisakawa, Mitsuki Saiga, Nana Mizuki, Romi Park, Rie Kugimiya, and Yui Horie, often have devoted international fanclubs. Some fans may watch a show merely to hear a particular seiyū. Some Japanese voice actors have capitalized on their fame to become singers, and many others became live movie or television actors.
In Japan there are around one hundred and thirty voice-acting schools. Broadcast companies and talent agencies often have their own troupes of vocal actors. Magazines focusing specifically on seiyū are published in Japan, with Voice Animage being the most well known and longest running.
The English term character voice (or CV), has been commonly used since the 1980s by Japanese anime magazines such as Animec and Newtype, for a voice actor associated with a particular anime or game character. Conversely, the Japanese term seiyū is commonly used among English-speaking anime and game fans for Japanese voice actors.
Initially, dubbing and doing voice-overs was a performance of an actor who used only his voice. When doing this job, they would be called "voice actors" (声の俳優 koe no haiyū ). For convenience, the term was shortened to a new compound consisting of the first and last kanji to make seiyū (声優). It was only after the seiyū booms however that this word became widespread. For this reason, elderly voice actors resent being called seiyū, because during their time the term had a different (and minimizing) connotation. The renowned Chikao Ōtsuka, who dubbed Charles Bronson among others, was quoted in a special issue of Animage saying "We are actors. Even if a performance only requires the use of our voice, we still remain actors, and it is therefore incorrect to refer to us as just voice actors, isn't it?". He was opposed to the new trend of separating actors and seiyū, even in the face of emerging seiyū like Genzō Wakayama, who learned how to act using their voice and never set foot in a theater.
There are three main factors that set seiyū and actors apart.
Voice acting has existed in Japan since the advent of radio. It was only in the 1970s that the term seiyū entered popular usage because of the anime Space Battleship Yamato. According to a newspaper interview with a voice talent manager, "Since the Yamato boom, the word 'seiyū' has become instantly recognized, before that actors and actresses who introduced themselves as seiyū were often asked, 'You mean you work for Seiyu supermarket?'" 
In 1925, the Tokyo Broadcasting Company (predecessor to the NHK, Japan's public broadcasting system) started radio broadcasts. In that same year, twelve students who were specializing in voice-only performances became the first voice actors in Japan when a performance of a radio drama was broadcast. They referred to themselves as seiyū, but in those days the term "radio actor" (ラジオ役者 radio yakusha ) was used by newspapers to refer to the profession.
In 1941 NHK opened a training program to the public to prepare actors to specialize in radio dramas.This was called the "Tokyo Central Broadcasting Channel Actor Training Agency" (東京中央放送局専属劇団俳優養成所 Tōkyō Chūō Hōsō Kyoku Senzoku Gekidan Haiyū Yōsei Sho ). Then in 1942, the Tokyo Broadcasting Drama Troupe debuted its first performance. This was the second time that the term "seiyū" was used to refer to voice actors.
There are several theories as to how the term "seiyū" was coined. One theory is that Oyhashi Tokusaburo, a reporter for the Yoimuri Newspaper, coined the term. Another theory is that Tatsu Ooka, an entertainment programming managing producer for the NHK came up with the term.
At first, seiyū, like those at the Tokyo Radio Drama Troupe and similar companies specialized in radio dramas; with the advent of television, the term took on the additional meaning of one who does dubbing for animation. Television broadcasting aside, when radio was the leading mass medium, actors who played in radio dramas were not without their fans; for example, actors in the Nagoya Radio Drama troupe who played the lead love interest roles often received many fan letters.