I tried it by accident, but stayed for the dynamic between leads, the acting of the whole cast, a good story line (but the are were some trips while nearing the end), and definitely for the OST. It's rare for me to watch the opening for more than few times, but I've been watching it at the beginning of every episode. I recommend watching it if someone like this kind of stories. The suggestive and rather direct way of telling the genre specific relationship might be a bit... too direct for some, but the fighting scene, the humor and the development of characters is really worth watching.