Hindsight (Hangul: 푸른소금; RR: Pureun Sogeum, lit. Blue Salt) is a 2011 South Korean film by Lee Hyun-seung, his first after a ten-year hiatus. The film is about a hitwoman who struggles with feelings for the underworld boss who is her target. The film deals with issue of age difference and the Korean underworld, specifically gangs. It stars Song Kang-ho and Shin Se-kyung, and premiered at the 16th Busan International Film Festival. The film received a total of 763,776 admissions nationwide.
Busan, South Korea, the present day. Legendary retired gangster Yoon Doo-hun (Song Kang-ho) dreams of opening a restaurant, and enrolls in a cookery class, where he gets to know Jo Se-bin (Shin Se-kyung), 20. Doo-hun then hears that his former boss, Man-gil, has died after being hit by a car; the gang’s members need to find Man-gil’s will to see whom he nominated as his successor, though most of them expect it is Doo-hun. Meanwhile, Se-bin’s roommate Lee Eun-jung (Esom) has become indebted to some Haeundae moneylenders, who force Se-bin, in return, to spy on Doo-hun. After Eun-jung steals a suitcase containing cocaine from the moneylenders, Se-bin is ordered to kill Doo-hun but can’t bring herself to do it. Instead, Eun-jung tries to run him over with a car and subsequently disappears. Doo-hun survives and takes over as head of his old gang, intent on discovering who killed Man-gil. Among various problems, he has to contend with Baek Kyung-min (Lee Jong-hyuk), an ambitious young member of the gang, and his continuing relationship with Se-bin, who is under pressure from assassination agency head Madame Kang (Yoon Yeo-jeong) to kill him.