It's an odd thing, and Sanji knows that it's impossible to love someone who died years ago, but he gets pretty damn close to it anyways.
At first it had only been a vague curiosity, a simple desire to know what the woman who could raise two such high-spirited and assertive daughters might have been like.
So he acts on it.
He asks Nami's sister for her diaries and he sees what she looked like from the photograph on Nami's bedside.
She is... intriguing, to say the least.
She had been given the short end of the stick in life, had turned things around with her own power, had followed her dream and become a marine, had saved tens of thousands of lives, had delivered many a solid punch to many a deserving pirate.
She had developed a liking to tobacco, much the way he had, at an early age. She had trained herself to be strong against any and all the odds that flew at her, and boy were there plenty.
She could hold her own any day, Sanji knew.
Slowly, as the sun dips down lower and lower and finally nips out of sight, the candle on his table would continue shedding inches upon inches of wax as Sanji reads about the woman with a curious, insatiable obsession, oblivious to both sun and moon.
Slowly, his conversations with Nami elapse into nothing but the woman, Sanji asking Nami to tell him more about what she liked, what she would do when faced with a certain situation, what were her habits, and generally getting to 'know' the woman.
It catches on so much with him that even Luffy begins giving him weird looks whenever Sanji talks about her.
He even dreams of her, or what he thinks she would look like. In his dreams she is always dressed the comfortable way Nami describes, in the green checked shirt that he has seen in the many pictures of her he has accumulated, and she would like his company, and he hers.
The desire in his chest to meet the real thing would grow, and grow, and grow, until Sanji thinks his heart will burst. However, the dead remain dead, and no matter how many times he dreams of her he is unable to shake off his deep, devouring desire to meet the real her.
In his dreams, she is always elegant but rowdy, feisty but demure and playful but polite all at the same time. She is the sort of – no, the exact woman he would have liked to meet very much in reality, and make friends with, share a chat over a really good movie and a cup of tea.
She would make him that special orange sauce of hers that Nami claimed was so delicious, and he would tell her what she could make it better with, and together they'd all make it just perfect.
But dreams always end.
He knows that his dreams are just about the closest as he can ever get to her, the huge number of leather-bound journals the only thing that remains of her, the picture by Nami's bedside the only time he will look at her, and still he cannot stop.
As he has said before, it was pretty much impossible to fall in love with someone who's dead and six feet under, but well, there's no harm in trying, is there?