There is steam in:

Naked Kitchen
Love to Eros

Tears and steam:

A Million Stars Falling from the Sky

Big Spoiler!!!! Watch only if you love spoilers!!!

Love Keeps Going Sunny Romance Devil Beside You If you haven't, then watch these movies- A Frozen Flower and Norwegian Wood.
I would suggest Devil Beside You and MARS .. I enjoyed them :) Queen In Hyun's Man was pretty good as well .. Lie To Me had like one good kiss scene I think but that's it ... I thought Hana Yori Dango was pretty good, comedy wise .. I liked the romance as well ... Flower Boy Ramyun Shop had a good kiss scene! ... I think that's all I got right now XD
About a year ago, during a long trip, I had four films DVD's so I watched them without any idea about the synopsis; Three of them were steamy: A frozen Flower, Portrait of a Beauty and Five Senses of Eros while the forth was an horror film. I wasn't actually pleased with them and I promised that I will never watch a film without reading its synopsis. It's horrible when you watch three steamy films in row and what makes it worse that I wished one of them was a Wuxia, horror or anything that would please me but sadly I had to watch the three of them back to back (What a horrible feeling I had back then) I believe that A frozen Flower had the most interesting story although I stiil believe that they could decrease the number of those erotic scenes; yes, they had an impact on the story but they could've been cut. As or me, I skipped half of them. Oh, I dislike the fact that this film was my first Jo In Sung's production. Seing him in this film destroyed any chance of watching any of his other productions :( A portrait of a Beauty could've been beautiful but it failed to do so and Nam Gil's character disappointed me. It's true that the story had some kind of depth but it annoyed me and created a bad feeling inside me. Five senses of Eros was an erotic film that contained many stories and I am so glad that I didn't see many actors that I appreciate naked in this or I would've feel really disgusted. This film left good question marks but I really didn't like it mainly because it was the third steamy film I watched therefore the previous two created an annoying feeling that made me dislike this film the most. The last was an horror film that pleased me so much after this horrible experience. It's a given that horror films can always cheer me up :)
I Need Romance had a lot of steamy kissing scenes Queen Inhyeon's Man also had some nice kissing scenes
I would like to suggest Love Lessons. I watched it raw but somehow I understood how it goes. Its very steamyyy. 
P.s. You should be 18 and above, and open minded to watch it lol Although I'm not yet 18 but whatever.Haha. 
Although a lot of people did not like LIE TO ME for me the chemistry was  real, plus the kisses were kisses not some kind of statue kissing. LTM is one of those dramas that still gives me goosebumps. I will never forget Soda Kiss! Give it a try and see how you might like it. I also liked BOSS & ME. The kissing scenes were good, and a lot of hidden romance was present in the drama that made me feel all soft inside. Perhaps not many people would agree with me on both, but for me these two were pretty romantic and hot. 
I'd suggest Secret (2013); the romance starts slowly but it was pretty intense and with a very passionate kissing scene
Frozen Flower (2008) seen on dramacool and it was Ok, plus it is steamy but Green Chair (2005) has much more nudity and bed scenes and it's definitely a lot of that there. Definitely not allowed below 21 I would say even 18 is a bit too much. 
I watched I Need Romance 3 at first and there was some kissing, but someone said in this post I Need Romance has pretty good steamy scenes... and Yes! It starts pretty hot and continues with some good kissing. So if you want to watch I Need Romance series go for it :)
My next choice would be Temptation of Eve - 4 different parts with nudity and really freaky/horror/bloody stuff. That was one of these series I watched by accident and I liked it for the part it was some crazy stuff there and first time I saw that much nudity in Korean movies. TOE you can find here : http://www.drama-tube.com/playing/?ap=1434468878%7Ckorean-drama%7C58nf0eHC5Mri4ZHhx5rG5sY%3D&tt=ES&epi=&sp=1  (by the way that site has everything when it comes to asian dramas - one of my fav sites so far. 
did anyone recommend Just You yet? ;0 idk if it would be your cup of steam though.. 
  • Addicted (K-film) - I know many people don't mess with Lee Byun Hun right now, but the movie is still pretty steamy. Can get boring at some points, but the overall story was interesting. 
  • Plum Blossom (K-film - I feel like someone had already mentioned it. 
  • Second Love (J - drama) - It's only seven episodes, but definitely the most steamy j-drama I've seen period. But it was still a pretty disappointing drama honestly.  
Lady & Liar! Its a lot like Cruel romance
Secret Love Affair is so intense it leaves me breathless. It's not even just the kisses, it's the way that piano playing is used as a metaphor for sex and it's HOT HOT HOT. And if you can sit through the politics part of the drama it's a really good watch.
If you haven't watched yet, I suggest THEY KISS AGAIN. :D It is a Taiwanese drama, a sequel of It Started With A Kiss. Ariel Lin and Joe Cheng really portrayed the role of being a husband and wife there. You can watch it here. Kekeke :)