"Doors (Yūki no Kiseki)" was used as the theme song for television drama Saki ni Umareta dake no Boku starring member Sho Sakurai, and "NOW or NEVER" was used in a Puzzle & Dragons commercial.

The first-run limited edition 1 will have a CD containing two songs and a karaoke track, and a DVD containing music video and making of the single "Doors (Yūki no Kiseki)."

[3] "Doors (Yūki no Kiseki)" is used as the theme song for the television drama Saki ni Umareta dake no Boku, starring member Sho Sakurai, which was first broadcast on October 14, 2017.

The song is described as a warm, but powerful, slight ballad that contains a message about the importance of looking ahead and moving forward even though a person may have problems in relationships with other people.

[3] The lyricist RUCCA stated that he wrote the lyrics based on the theme in drama Saki ni Umareta dake no Boku.