[1][2] On April 22, 2019, Netflix announced through a press release that it would distribute a new Korean original series entitled Extracurricular and produced by Studio 329, confirming at the same time that the main cast would consist of Kim Dong-hee, Jung Da-bin, Park Ju-hyun, Nam Yoon-soo, Choi Min-soo, Park Hyuk-kwon and Kim Yeo-jin.

[6][7] On April 28, 2020, the press conference was held online due to the coronavirus pandemic, in presence of actors Kim Dong-hee, Jung Da-bin, Park Ju-hyun and Nam Yoon-soo, executive producer (and Studio 329's CEO) Yoon Shin-ae, and director Kim Jin-min.

[8] The series being released a few months after the Nth room case opened, director Kim said that "the incident was so shocking that [he] felt frightened.

"[9] On April 29, some of the cast and crew attended a special one-day class by Professors Kwon Il-yong (South Korea's first profiler), Park Mi-rang (a criminologist) and Seo Min-soo (from the Police Human Resources Development Institute), which was broadcast live on Netflix Korea's YouTube and V Live channels.

The debut episode's near-miss ending isn't entirely satisfying, but that's not likely to stop you from binging the crap out of this show.