The breakthrough yearIn September 2022, the year he turned 24, he appeared in episode 15 of TVING EXchange 2 as the last cast member. JTBC writes that his appearance drew an outsized response from viewers.
In the Oct. 28 finale, he became the final couple with Sung Hae-eun. In January 2023, he said on the web variety show Bakwi Dallin Ip 3 that he got into Seoul National University on his sixth try. In February, he said he had sued people who left malicious comments, and he attended the agreement ceremony of GS Retail and the dessert café Billow.
In December 2024, it was reported that he would appear in the new season of The Devil’s Plan. Filming had wrapped that August.
In January 2025, he announced a YouTube channel, and on March 24 he began working on it in earnest with “Seoul National University Cafeteria Vlog!” He attended the press conference for The Devil’s Plan: Death Room on April 29, and in the show, released on May 6, he won the final episode on May 20 and received a prize of 380 million won.
In his winner’s interview on May 27, he said he was sorry for causing discomfort with his words and actions during the broadcast. The same day, he ranked No. 1 among non-drama cast members in a buzz survey for the fourth week of May. On June 1, he posted a reflective message on his YouTube channel, and in July he attended the Blue Dragon Series Awards red carpet.
In April 2026, a pictorial for MAPS shot in Tokyo, Japan, was released, and in May he did a month of student teaching. In September, he posted photos and videos from the Seoul National University festival on social media.
Jeong Hyun-gyu (born 1998) became known on Sep 23, 2022, the year he turned 24, when he appeared as the last cast member of TVING EXchange 2, and won the finale of Netflix The Devil’s Plan: Death Room on May 20, 2025, the year he turned 27.
Ages are by calendar year (the year minus the birth year), birthdays aside.