Shin Su Hyun

Sungjin High School is thrust into chaos as an alien invasion begins, unleashing violent insect-like creatures worldwide. With the South Korean military overwhelmed, mandatory conscription is imposed on all third-year high schoolers, forcing them to undergo military training while facing impending university exams. Platoon leader Lee Chun Ho guides them through rifle shooting, combat, and obstacle courses, all in their school uniforms. Class teacher Park Eun Young strives to protect her students. Can these high schoolers become saviors in the face of global doom? (Source: MyDramaList) ~~ Adapted from the webtoon "Duty After School" (방과 후 전쟁활동) by Ha Il Kwon (하일권).

Yun Ga Min, a student at the struggling Yusung Technical High School, is determined to go to college despite his poor grades and knack for fighting. He forms a study group but is forced to use his fighting skills to protect his friends from bullies. His teacher, Lee Han Gyeong, who tutored him while he was a middle school student, returns as a temporary teacher with a secret and hopes to improve the school. (Source: MyDramaList) ~~ Adapted from the webtoon "Study Group" (스터디그룹) written by Shin Hyung Wook (신형욱) and illustrated by Ryu Seung Yeon (류승연).