Yes, quirky. Yes, I know Joon is suffering from a mental illness, but this isn't an either-or situation - she can be both.
With a cast of interesting characters, a great concept for a poker game, and sets that match the characters so well, this has been one of my favorite movies since the first time I saw it. Wounded, confused hearts recognize and reach out to each other, and can heal each other.
Other reviewers note that Joon's mental illness is inconsistent, debilitating, and not accurately portrayed. I recognize this and am so smitten by this film that I disregard the potential inaccuracies of this portrayal. I see her as learning, still, as we all are, how to function appropriately. Stress and change in routine seems to cause the breakdowns - learning to work with that (both her and those around her) may help her heal. Hope spring eternal.
Sam is lovely, fun, and confused by the world, a man out of his tree and out of his time.... And the combination of the two of them working is magical to me.
The other primary couple in the movie, Benny & Ruthie, also have their own quirks, but not as extreme as Joon & Sam.
Perhaps the message of the movie is that no matter how bizarre you may be, you can find someone for you. If that person understands and embraces your quirks, lifts you up in your darkest times, and helps you to be better - we should all be so lucky.