Sensual Phrase (Japanese: 快感 フレーズ, Hepburn: Kaikan Furēzu) is a Japanese manga series written and illustrated by Mayu Shinjo. The manga was published by Shogakukan in Shōjo Comic between 1997 and 2000, and collected in 18 bound volumes. It was adapted as a 44-episode anime television series by Studio Hibari, and as a series of novels. The series tells the story of Aine Yukimura, a high school student who becomes the lyricist for a Japanese rock band, and her relationship with the band's lead singer, Sakuya Ookochi.

To promote the anime, a real-life band was formed: Λucifer, the band the story focuses on. The rival band, e.MU, seems to have been active before the manga was created. Both bands continued after the anime ended before disbanding. In the series, Λucifer's original name is Lucifer, changed to Λucifer (using the Greek letter lambda) when the band decides to go international. For the purposes of the article this second name, Λucifer, is used. Japanese names are given in Western order, with family name last.