Soo-jung is struggling to receive a promotion as a permanent teacher at Seolsong and was unwittingly scammed to pay a hefty sum of money to become one.

His heroic action forces Se-ho, recently promoted to become Seolsong's board chairman, to re-admit Bok-soo into the school and appease public opinion.

The ensuing scrutiny convinces Se-gyeong to depose her son and engineer a scapegoat so the school's reputation could be protected.

Se-ho, having had a change of heart and sick of being mistreated by his mother, forms an alliance with Bok-soo to further scrutinize Seolsong and bring them to court.

Bok-soo, Soo-jung, their friends, and the teachers band together to prevent her from entering the school long enough until the police arrive to arrest her, having been tipped by Se-ho regarding his mother's crimes.

Se-ho moves to the United States to recover, while Bok-soo receives his high school diploma a year later.

The first script reading took place on October 8, 2018 at SBS Ilsan Production Studios in Goyang, Gyeonggi Province, South Korea.