[1] After the band's EP É in 2017, they worked on their first studio album.

The tracks Peter Parker (피터 파커) and Tomato Homicide (토마토 살인사건), which were decided to be excluded from the É tracks, were included in the album.

[2] The album is a concept album, and the album is divided into the first part of "Inside," where the speaker cuts himself off from the outside world where disease is prevalent, and the second part of "Outside," which the speaker, who has been observing the outside through the window inside, experiences and feels as he goes out.

"[5] The member of the selection committee for the Korean Music Awards Lee Kyeongjoon reviewed, "Decadent is an album that breaks down the boundaries between rock and modern rock.

[6] Web magazine Tonplein described the Tomato Homicide (토마토 살인사건), the track of the album, as "the track that represents us in the South Korea where we live by suppressing the anger that we want to kill, smash, and overthrow everything, and faces the present of the country.