When Sawoo gets bullied in high school, his only friend Kido promises to teach him how to become the greatest villain.
But Kido goes overseas after teaching Sawoo only two of the three rules.
Faithfully following the two rules, Sawoo writes Kido many letters in the hope that he will get to learn the last remaining rule but Kido never replies.
One day after four years, Kido shows up in front of Sawoo, thinking those were love letters.

Choegoui Agdang,
Best Bad Guy ,
Very Bad Guy,
Лучший «плохой» парень,
你好壞我好愛,
你好壞我好愛,
最佳惡魔,
最高の悪黨,
최고의 악당