Ireland, aka Aillaendeu, is a mini-series about the lives of 4 people.
Lee Jung-a (Lee Na-young) is a medical doctor with a severe depressive illness that requires daily medication to control. Adopted as an infant by an Irish family, she returns to Korea after witnessing their violent deaths.
Kang Guk (Hyeon Bin) is a kindly security guard who works in a plush hotel that frequently houses movie stars or otherwise famous and successful people. He can't stop himself from reaching out to those who need help, whether they ask for it (or want it) or not. In Lee Jung-a, he sees such a person.
Lee Jae-bok (Kim Min-jun) is a twenty-something guy with few prospects. He's not very smart, and poorly educated, but he has charm, enough to be able to sponge off his actress girlfriend.
This girlfriend (Kim Min-jeong) is working in the blue movie industry and desperately trying to break into legitimate movies. Not only does Jae-bok sponge off her, so do her parents and her four brothers and sisters.
The plot is quite simple - it turns out that two of these four people are actually brother and sister. The complications come from their not knowing this fact, and consequently falling in love.
The adoption theme is common enough, particularly in Korean dramas, but incest as a topic for a sudsy drama is quite novel, and perhaps a bit touch and go. Nevertheless, it's very well-acted and worth watching. Hyeon Bin in particular manages to make a potentially weak and effete character into something resembling noble, and Lee Na-young is one of the most effective on-cue-weepers I've ever seen.
If you're a sensitive soul who hates seeing kind people treated badly, have the tissues ready and settle back for some fine entertainment (a whopping 960 minutes of it).