On March 31, various media outlets reported that idols EXO's D.O. and F.T. Island's Hongki were newly cast for the ROK army's musical production, 'The Promise of the Day'.

In response to the reports, the production company of 'The Promise of the Day' spoke up with a statement saying, "Nothing is confirmed regarding D.O. or Hongki's casting, and we are currently discussing casting options with the army. All factors such as roles, schedules, and more are still under discussion."

Meanwhile, the 2019 showings of 'The Promise of the Day' featured numerous idol stars as part of its cast including SHINee's Onew, EXO's Xiumin, VIXX's N, INFINITE's Sungyeol, Jo Kwon, INFINITE's Sunggyu, Yoon Ji Sung, etc.