Anyone who says this movie is bad and they didn't understand it is because they are basement virgins.
As for the ending, it's about being cured. What is a cyborg worried about rain for? Why is she camping out finally for their mission and have snacks and she's even worried about the wine getting water in it? Why would she need a band-aid if she's a cyborg? The last thing mentioned was socks being wet. Why would she need clothes if she's a cyborg? It's come to a realization that the experiment and love from another patient is what cured her. The build up from the start all the way up to the final moments totally helped achieve this.

good ending. they're looking for the lightning bolt that start the chemical process that started organic life. they that are intentionally being there are not looking for some accident that will change their life but putting themselves in condition that will change their life. the lightning bolt does not strike but the rainbows appears- the intention for change is more important than the lightning bolt actually hitting their lightning rod. its a simple story Young-goon contracted insanity from her grandma. Il-sun;s insanity come from some traumatic experiece. both need human contact. Young-goon needed help, il-sun needed empowerment- that he got in helping Young-goon. both eventually help each other in burying their traumas.

It is really interesting to read the comments on this thread! The ending is simple and makes perfect sense. I agree that this is a feel good film, but it is also intricately and intelligently done, and can be examined on a deeper level.
I liked this movie way more than Oldboy, and I do not plan on watching "Revenge" trilogy those are not my type of films.
For the people who said that the beginning dragged on and didn't make sense, and that the end was haphazard, I have to say that I respectfully disagree. I believe that every scene was deliberate in character development and plot movement to completely understand what is going on.
For example, the scene where the girl who has been practicing her singing for 31 years and the elastic band man explain their disorders makes way for the "transfer" that gave Rain the ability to sing and the "flying socks." That in turn leads to the grassy plains scene that signifies the grandmother's death (the elastic band was pulling tighter and tighter) and her parting words that the protagonist could not "decipher" until the end of the film.
I think Chan-wook Park would be disappointed to see that his audience/following could not understand and appreciate his work with an open mind. It seems like having an unsavory/disagreeable following is the by-product of making critically claimed general public films.
I still feel like this movie is a near masterpiece, and it is unfortunate that this film does not at least have a rating of a 7.5 on this site.
But I also respect that people have different tastes. Cheers!

In some instances the ending of a story isn't as important as the journey there. This is clearly the case in this film, its not difficult to understand what happened either. Some things just aren't meant to be spelt out in black and white.

I don't see them naked at the end. I see them wearing clothes.
I was also wondering if lightning HAD hit them after all because I didn't see them moving. Maybe they both died in the night, hit by lightning, and the rainbow was symbolizing they went to heaven.

This message has been deleted.

i was also super dissapointed. oldboy got me watching korean moviesbut this one, i just lost intrest half way through it, its bad when you dont care for any of the characters.
^I agree with this comment. I wanted very much to like this film as I have enjoyed the director's other work. Unfortunately I found that I did not care for the characters at all because they were pretty one dimensional so I lost interest very quickly. Focusing on the quirks and 'neuroses' of the characters is just a poor attempt to distract us from the lack of story/direction

I'm at a loss with people. Every one of Park's films except JSA is not, at it's base, about what is shown to the audiencePark leaves hints here and there, clues as to what is really going on. Oldboy is the film that basically telegraphs what all the action was really about, and while I'm not 100%, I think Cyborg is the same, where what we're seeing happen isn't actually happening - all his films are about how we deal with dilemmas and regrets internally, not externally.

Actually the movie is funnily entertaining and has a lot of intellectual subtext. Not very many dramatic comedies have that going for them.

The ending is a bit poor, but the movie is not so bad.
Oscar from Rosario City
Argentina

I LOVED Amelie and that's saying something, I'm generally really not into romantic comedies, they just aren't my thing. But I loved this and Amelie, it's not shoving anything down your throatnot too cutesy or sappy, it just FEELS good and that's what true art is about, eliciting a feelingdark, light, happy, sadall secondary to making the viewer feel.
+Charos+
"I have often laughed at weaklings
who thought themselves good because
they had no claws."

Agreed. Anyone who thinks this movie is bad is an idiot. It's a light hearted, entertaining, feel good film that does exactly what it's supposed to do. It's not meant to win awards, it's not meant to make you think for hours about the meaning, it's just a lovely, charming little film. It's clever, innovative, funny and moving. OH MY GOD PARK CHAN WOOK MADE A ROM-COM. Jesus, grow up. He made 4 dark films in a row, give the man a break if he wants to do something a little more light hearted. The people who dislike this film are people who probably dislike Amelie aswell. To that, again, you are morons.