Most romance anime are made with the intention of portraying how a perfect relationship would be with character personalities that are just not possible in real life. This anime does exactly the opposite of that. In Nana, you are shown the flaws of every character and shows how real life is not as pretty and perfect as we expect it. You can look at the animated characters and realize that they could very well be someone in real in life, someone you have met, or even you.
We like to dream and imagine how our ideal life would be only to realize that things change, we make mistakes, and life doesn't always take us to where we initially wanted. This anime is basically an animated portrayal of the imperfect life of imperfect people and how their actions, mistakes, and regrets, take them to where they are.
