When it says its 15 eps, they are short, it takes about 90mins in total, so there is no waiting for things to happen, there are no filler side plots. It's like a good play. The story works because the basic setting is based in reality, if you have seen student housing, it is normally small, with paper thin walls, and irregular plumbing and electric to match.

The comedy not on comes from the actual situations, but highlighting k-drama tropes in the best possible humorous way. If you like situation comedy where people will do anything not to ask a direct question and that leads to ambiguity . I thought only the British did that level of embarrassment humour,
The physical comedy is well done, even the set karaoke scene looked fresh, and of course with acting was excellent. The tease at the start of the episode to lead the audience on very cleaver.
The overall joke that two now established romantic ML behaving like geeks, in roles they would probably never be cast in now, gives you a sly smile.
I am giving 9.5 because it would be viewed as a whole. The best k-drama for comedy I have seen, it's going to be a cheer me up rewatch.