Translation guide
A theme song is a piece of music associated with a TV show, movie, game, or event. In Japanese, the most common and natural way to refer to this is 主題歌 (shudaika). There are also more specific terms for opening and ending songs, as well as related concepts like image songs and insert songs.
The main song associated with a show, movie, or game.
The standard, all-purpose word for 'theme song'. Used for TV shows, movies, anime, games, etc.
このアニメの主題歌はとても人気があります。
The theme song of this anime is very popular.
映画の主題歌を歌っているのは誰ですか？
Who sings the theme song for the movie?
A loanword from English, also commonly used. Slightly more casual and often used in promotional contexts.
新ドラマのテーマソングが発表されました。
The theme song for the new drama has been announced.
Literally 'theme tune'. Can refer to instrumental themes as well as songs. Common for movies and TV.
この映画のテーマ曲は有名な作曲家が作りました。
The theme tune for this movie was composed by a famous composer.
The song played at the beginning of a show.
Standard term for 'opening theme'. Often shortened to 'OP' (オープニング) in casual contexts.
このアニメのオープニングテーマは毎回聞いています。
I listen to this anime's opening theme every time.
A slightly more casual way to say 'opening song'. Often used in conversation.
オープニング曲がかっこいいですね。
The opening song is cool, isn't it?
The song played at the end of a show.
Standard term for 'ending theme'. Often shortened to 'ED' (エンディング) in casual contexts.
エンディングテーマが流れると、ちょっと寂しくなります。
When the ending theme plays, I feel a little sad.
A slightly more casual way to say 'ending song'.
このエンディング曲は名曲だと思います。
I think this ending song is a masterpiece.
A song associated with a specific character or concept, not necessarily used in the show itself.
A song created to represent a character or the world of a series, often released on character albums. Not used as an opening or ending.
このキャラクターのイメージソングは、声優さんが歌っています。
This character's image song is sung by the voice actor.
Abbreviation of 'character song'. Very common in anime/game fan communities.
推しのキャラソンをヘビロテしてます。
I'm playing my favorite character's song on repeat.
A song played during a scene within a show or movie, not at the opening or ending.
A song inserted into a specific scene, often used for emotional impact.
あのシーンの挿入歌がすごく印象的でした。
The insert song in that scene was really impressive.
主題歌 is the most standard and widely understood term. テーマソング is a loanword and feels slightly more modern or commercial. テーマ曲 can refer to instrumental pieces as well as vocal songs, so it's broader. In most everyday situations, 主題歌 is the safest choice.
主題歌を教えてください。
Please tell me the theme song.
テーマソングが流れるとテンションが上がる。
I get excited when the theme song plays.
In anime and game fan communities, it's common to abbreviate opening and ending themes as OP (オープニング) and ED (エンディング). You'll often see phrases like 'OPが神' (the opening is god-tier). These are very casual and mostly used online or among fans.