Rounded up from 2.5 stars simply because, for my money, Song Kang-ho is one of the world's great stars and carries several scenes here just by waiting a beat and then smiling... and, um, because I'm irrationally biased in favor of Korean cinema. To a certain degree one can overlook the empty glossiness of production and equally shallow sentimentalism--those often come with the territory if one is expecting a multi-genre, popcorn-fueled blockbuster. In other words, I would have been very happy with another "Secret Reunion" (2010). Of course it's fine that here we have a romantic subtext instead of bromantic one, but what's not fine is how undercooked it is and how anemic the action scenes are on top of that. As an example of how neither angle works, I proffer this image: an undeniably cute and appealing Shin Se-kyung takes aim with a high-powered rifle but then director Lee Hyun-Seung has her gently bite her lower lip in hesitation. If you feel that sort of thing adds extra dimension to female characters or more heft to dramatic tension, knock yourself out, but I found "Hindsight" hard to take seriously after that point. The same was true following two scenes in which the leads separately endure the kind of physical assault that would land the rest of us in hospital beds but from which they bounce back so quickly that it's as if the characters themselves had stunt doubles.