Jang Sung-Gi is the main protagonist of Skill of Lure. He is consistently misunderstood and branded as a pervert.
Sungi-Gi's appearance can be described as above average with brown hair and brown eyes.
Jang Sung-Gi is an intelligent person with a good heart. He is willing to help out anyone who asks him for help, regardless of their behavior towards him. He is willing to risk his life for the people he loves. However he is very gullible.
While stretching in class Sung-Gi accidentally flips up An Sea Na's skirt who happened to be walking past. As the whole class watches, he immediately claims his innocence only to be reprimanded by the girls in mixed class A as a pervert and beaten up. On entering the train ride home, he notices he notices that the compartment is full of women, so in order to avoid being in perverse situations he uses his gentlmen pose.
Eventually he gets up from his seat only to accidentally bulge his face into Lee Yura's chest. As he moves back in shock, he loses his balance and uses the chest of the women sitting next to him stabilise himself. He is eventually beaten up by the women on the train and branded as a pervert.
The next day, Sung-Gi notices a man smoothly breaking up with his girl friend. On seeing this he ponders why he is unable to interact with women as casually as the man. At Ganda Institute Sung-Gi is approached Na Hwang Jae regarding a maths problem. When Sungi-Gi is asked if the reason he looks down is due to a women, he rejects it. As Hwang Jae leaves, he notes that Hwang Jae will be the last person he will turn to, if she wants advice about women and he is more worried about him. As he is walking along the corridor he notices a brick like object about to fall on Lee Yura from the top of the lockers. Immeadiatley he rushes towards her to push her out of the way, only to be end up groping her lower body with his. On yet again realising he is an perverse situation, he immediately apologises, as other students watch on. As he realises the that the brick is sponge, he immeadialty hate himself and starts to silently break down in the middle of the corridor.