Study Group (2025) featured a cast of 29 tracked actors. Of these, 29 (100%) are still alive today. The oldest surviving cast member is Jeong Jae-seong, age 55. This TV series starred Minhyun and Lee Jong-hyun.
100% still with us· verified cast
Survivorship
Cast Reunion Index: 100% still living
Cast29 members
| Person | Character | Status | DOB | Age | DOD | Age in 2025 |
|---|---|---|---|---|---|---|
 Minhyun Yoon Ga-min | Yoon Ga-min | Living | 09/08/1995 | 31 | — | 30 |
 Lee Jong-hyun Kim Se-hyeon | Kim Se-hyeon | Living | 01/08/1998 | 28 | — | 27 |
 Gong Do-yu Lee Jun | Lee Jun | Living | 20/01/1994 | 32 | — | 31 |
 Shin Su-hyun Lee Ji-woo | Lee Ji-woo | Living | 27/02/1996 | 30 | — | 29 |
 Cha Woo-min Phi Han-wool | Phi Han-wool | Living | 24/10/2000 | 25 | — | 25 |
 Park Yoon-ho Lee Hyun-woo | Lee Hyun-woo | Living | 03/04/2003 | 23 | — | 22 |
 Hong Min-gi Park Geon-yeop | Park Geon-yeop | Living | 12/03/2002 | 24 | — | 23 |
 Han Ji-eun Lee Han-kyung | Lee Han-kyung | Living | 03/06/1987 | 39 | — | 38 |
 Jeon So-young Jang Min-hee | Jang Min-hee | Living | 27/03/2002 | 24 | — | 23 |
 Yun Sang-jeong Choi Hee-won | Choi Hee-won | Living | 17/01/1998 | 28 | — | 27 |
 Kwon Sang-woo Jeon Young-ha | Jeon Young-ha | Living | 05/08/1976 | 50 | — | 49 |
 Baek Seo-hoo Ma Min-hwan | Ma Min-hwan | Living | 25/08/1996 | 30 | — | 29 |
 Kim Su-gyeom Choi Moo-kyu | Choi Moo-kyu | Living | 03/12/2001 | 24 | — | 24 |
 Lee Gwang-hee Jeong Do-hoon | Jeong Do-hoon | Living | 03/11/1997 | 28 | — | 28 |
 Kim Young-ah Jeon Mi Hyun | Jeon Mi Hyun | Living | 24/05/1975 | 51 | — | 50 |
 Yoon Hyun-suk Ji Young-hyun | Ji Young-hyun | Living | 08/09/2001 | 25 | — | 24 |
 Jeong Jae-seong vice-principal (Yu-seong Tech) | vice-principal (Yu-seong Tech) | Living | 16/12/1970 | 55 | — | 55 |
 Joo Yeon-woo Kim Soon-cheol | Kim Soon-cheol | Living | 06/11/1992 | 33 | — | 33 |
 Cho Seung-yeon dean of academic affairs (Yu-seong Tech) | dean of academic affairs (Yu-seong Tech) | Living | 14/04/1972 | 54 | — | 53 |
 Jin Woo-jin Kim Gyu-Jin [Disciplinary Committee member] | Kim Gyu-Jin [Disciplinary Committee member] | Living | 19/08/1993 | 33 | — | 32 |
| Living | 15/08/2011 | 15 | — | 14 | ||
 Kim Min-ah Hwang Mi-Hee (Yu-seong Tech) | Hwang Mi-Hee (Yu-seong Tech) | Living | 15/12/1999 | 26 | — | 26 |
Lee Dong-Hoon Seo Yoo-bi | Seo Yoo-bi | Living | 16/05/1997 | 29 | — | 28 |
 Kim Hwi-gyu No. 173 | No. 173 | Living | 08/01/1992 | 34 | — | 33 |
 Ma Hyun-ji Hong Jae-hui | Hong Jae-hui | Living | 27/01/1998 | 28 | — | 27 |
 Shin Seo-woo Kim Se Hyeon | Kim Se Hyeon | Living | 13/08/2013 | 13 | — | 12 |
 Lee Chang-In Nam Sang-woo | Nam Sang-woo | Living | 22/08/1999 | 27 | — | 26 |
 Mo Geon-hu Kook Gwan-u | Kook Gwan-u | Living | 12/01/1998 | 28 | — | 27 |
 Lee Woong-jae Yoo Joon-min | Yoo Joon-min | Living | 03/07/2003 | 23 | — | 22 |
