On the June 24 episode of KBS 2TV drama, "Unexpected You," featured Cha Se Gwang (Kang Min Hyuk) waiting for Bang Jang Goon (Gwak Dong Yeon) at a family restaurant. Bang Jang Goon appears with his friend Park Man Shik (Lee Ji Oh). Jang Goon asks, "Why did you call me out all the way over here?" Cha Se Gwang then pulls out his proof of enrollment from KAIST, the school he is currently attending. He then says, "This document is the proof of my enrollment that I'm attending this school. See? This is concrete proof, right?"
Jang Goon begins to look at the document without even blinking and says, "I'm sorry but do you know how many people in the world have the same name?" and doubted Cha Se Gwang's intelligence once again.
Jang Goon's friend, Man Shik also commented, "I agree with him. It is definitely a possibility that there is somebody else who has the same name as you do. There was a kid named Kim Se Gwang in my kindergarten class." Jang Goon then adds, "One of my dad's friends' name is Jang Se Gwang."
Cha Se Gwang was so dumbfounded that his mind went blank. Jang Goon then states, "You seem more suspicious because you're getting angry at the fact that I don't believe you," and disappears with his friend Man Shik. Se Gwang then speaks to himself, "Why do I have to prove my intelligence to 'dumb and dumber'?" and becomes even more frustrated.
Even in the previous episode that aired on June 23, Jang Goon was discontent with the lesson Se Gwang was teaching during their lesson. Jang Goon says to Se Gwang, "I'm going to have to take the standardized math test, but why do we keep studying Korean history instead of math?" Se Gwang gave him the response, "I told you that even though the term sounds like math, is it not the same math that you think it is."
Jang Goon's question revealed his faith in his teacher's competence and demanded proof of his intelligence, and ever since then, Cha Se Gwang's pride went down as his student kept underestimating him.