Although Ahn Dae-seong has an excellent memory and perseverance, he still cannot pass the civil servant exam for several years. With the support of his mother and his policewoman girlfriend, he does not give up trying and is still working part-time at his mother's store on the outskirts of Seoul. When a murder occurs in the neighborhood, Dae-son finds out that the only clue that will help to identify the criminal is a receipt from their store.
