Gi-yeon is burdened by her half-brother's insidious gaze, but one day when he enters the bedroom, she decides to run away. Gi-yeon, who comes to Seoul for the first time, is caught by gangsters, but with the help of lightning, she gets out of trouble and lives with him in his apartment. Lightning, a member of a criminal organization, rejects Gi-yeon's pure love and for the sake of money, he makes Saron's regular customers Song Jeon-mu and Gi-yeon live. One day, Ki-yeon finds out that she is having a child of lightning. Lightning coolly shakes off Gi-yeon's hand, begging for her to live with her.
Kwon Dal-ho is a teacher who wants to make his 3rd grade class the best. Yu-dae becomes the class representative and Ki-pyo, the leader of the ten troublesome students who’ve been held back, transfers to his class to the chagrin of the other kids…
