Trivia: Shut Up Flower Boy Band

  • Contest Winner Cameo:
    • Yoo Min Kyu, who plays Ha Jin, isn't just making a cameo, but he won Flower Boy Casting: Oh! Boy reality show in order to be cast.
    • Kim Yerim, who is The Danza
  • The Danza: Kim Yerim (Two Months) of Superstar K3 fame
  • Dawson Casting: At the time of filming, Byung Hee's actor was 26-27, Seung Hoon's actor was 26, Ji Hyuk's actor was 21, Hyun Soo's actor was 19, etc. —all playing high school students.
  • Old Shame: Sung Joon (who plays Ji Hyuk) mentioned in a later interview that the show's title was "a bit embarrassing."