In episode 1, the It's Okay to Not Be Okay. This reunion of actors features the first of a number of guest appearances in this show.
In Episode 4, the Korean flirting meme popularized by Bae Suzy.
The episode 4 is Younha's Waiting (2006). keyboardist and background vocalist in performances and appeared in Younha's music video for Gossip Boy in 2008.
In Episode 4, the iconic line in The Great Queen Seondeok (2009).
Episode 4 shows a character watching the Korean drama "Crash Landing on You" (2019).