The song is based on a story submitted by a woman who describes feeling uneasy after being unable to reply to an e-mail from her ex-boyfriend.

"[7][8] "U & I" was broadcast on July 11, 2014, and was based on Jonghyun's relationship with his listeners, as he introduced the song saying, "Treat Blue Night like your diary and feel free to let me know your stories.

Jonghyun was influenced by multiple submissions where listeners often discussed taking a day off to rest from work and wrote a song to tell them to cheer up at their own pace.

The beginning of the song features a phone recording of a conversation between him and Wefreaky pianist So-jin, his friend from high school.

[7][12] "Diphylleia Grayi" was broadcast on April 10, 2015, the song using the skeleton flower as a metaphor for facing both external and internal struggles.