I have to agree with you that the 10 episode tradition of jdrama really helps them focus on telling a story. And I also like how they handle villains. Like it is in real life, even villains have motives that make sense and seem good to themselves. They don't wake up in the morning, rub their hands together and exclaim "Today I will be even more evil! Bwahahaha!" But that aside, it's the 10 episode format that keeps bringing me back to jdrama. After 10 episodes of anything, I am ready to stop watching, which is why I haven't finished a kdrama ever and stopped watching US dramas completely.