キャラクターソング

noun

character song; character theme song

A song performed in-character by a voice actor or associated with a specific fictional character, common in anime, games, and idol franchises.

wasei-eigo (Japanese-coined English), from character song

• このアニメのキャラクターソングは、声せい優ゆう本ほん人にんが歌うたっている。

  The character songs for this anime are sung by the voice actors themselves.

• 推おしのキャラクターソングを毎まい日にち聴きいている。

  I listen to my favorite character's theme song every day.