You know in all my time working I've only seen two office romances. I'm 31. Either the Japanese have a different attitude toward work, or it's exaggerated.
@Lyanhyrt It's exaggerated. You see it in US TV/movies/books/comics as well. It can make for an interesting story setup, or comedy, etc. so it gets used a lot in fiction. In reality it can cause a lot of problems (especially if the relationship falls apart) so it's not all that common.