Mnet's reality variety show "Reply High School" will air its fourth episode on the 6th at 8:20 PM. In this episode, legendary producer Na Young-seok and Go Joong-seok, CEO of Eggiscoming, will appear as guest teachers for a day. On the 2nd, Mnet released a teaser video announcing their appearance on its official YouTube channel.

"Reply High School" is an eight-episode series. The program follows SMTR25, a multinational boy trainee team of 15 from SM Entertainment, as they enroll in the fictional school "Ujeong High" and experience K-culture from the 1990s to the 2010s while searching for the key to their debut.

In episode 4, Na Young-seok PD and CEO Go Joong-seok will each conduct three special lectures on economics, variety shows, and fandom, respectively, to educate the SMTR25 trainees. In CEO Go's economics class, the members' quirky charms shine through. When Go asks, "What is S&P?" the members respond, "SM-style music...," causing surprise on set. This scene is expected to bring great laughter to viewers with the trainees' innocent reactions.

Na Young-seok PD's variety show class also draws attention. When Na PD asks, "What should you do when you are invited as a guest on a variety show?" the members immediately answer, "Be careful with what you say." Na PD exclaims, "100 points!" and smiles warmly at the cleverness of the variety rookies.

In the fandom class, the trainees take time to understand the hearts of idol fans, focusing on photo cards, a core element of fandom culture. By putting themselves in the fans' shoes and learning the meaning and value of photo cards, the members aim to offer empathy to fans and new enjoyment to the general audience.

Mnet's "Reply High School" episode 4 will be broadcast on the 6th at 8:20 PM on Mnet and Mnet Plus.