An Image song or character song is a song on a tie-in single or album (often called an image album or character album) for an anime, game or dorama that is usually sung by the voice actor or actor of a character, in character. It is meant to give a sense of the personality of the character.
Image songs are considered an important part of an anime or dorama's success, as they often provide insights to a character that may otherwise go unexplored on the program itself. The series creators may also include details about a particular character's design stages and evolution, and on occasion even design sketches so fans can see for themselves how a character changed. There may also be comments from the voice actors or actors on how they feel about playing their characters. Sometimes image songs are incorporated into the anime itself, such as Kyōran Kazoku Nikki, which has each of its main characters sing an image song as the ending theme, each with its own animation. Another example is Prince of Tennis, which has the openings and ending songs for the OVA episodes sung by characters in the anime.
Image songs are not restricted to anime protagonists. Antagonists such as Zechs Merquise, Master Asia, Sailor Galaxia, and some of the villains (such as Devimon and Dracule "Hawk Eye" Mihawk) also have their own image songs. In some cases, these are more interesting than those of the protagonists as they often provide the only glimpse into a villain's character.
In addition, fans are known to buy image song albums based solely on the voice actor or actor. An example of this is Megumi Hayashibara, a well-known voice actress who has released many CDs and albums over her career, including image songs of her characters.
The first anime image song album to reach No. 1 in the Japanese Oricon weekly charts is Hōkago Tea Time (放課後ティータイム After School Tea Time), performed by the characters from K-On! in 2009, debuting at No. 1 with the sales of 67,000 copies in its first week. The K-On! characters later became the first anime image group to reach No. 1 in the Oricon singles chart in 2010, with the opening theme for the second season of the show, "Go! Go! Maniac!", which debuted at No. 1 with the sales of over 83,000 copies in its first week.