Sanji, who made the decision at a very young age to never have biological children. The Germa gene experiments would die with him and he was... content with his decision, if anything.
Sanji, who grew up on the Baratie, where children were few and far between. They felt alien to him, even as a child himself, hard to understand and hard to talk to.
Sanji who is, in his deepest heart, afraid of children. They're so small, aren't they? So breakable?
And wasn't he a breakable child too?
Sanji, who does not want to admit that he's also afraid of himself. Zeff showed him what a real father could be, but then again, didn't Sanji have the blood of a monster running through his veins? The kind that hurts women and breaks children? It sickens him to think of what he could become, would become, if he fathered a child.
So no, he was never going to have biological children and was honestly unsure about adopting any either. Even if it wasn't by blood, who's to say that he wouldn't turn out exactly like Judge?
Life comes at you fast and suddenly, there was her.
The marimo, unable to find his way around his own ship, somehow found his way to an abandoned baby girl. He'd been missing for hours on the island before Sanji found him in a bar, feeding his new companion with a milk bottle he'd found somewhere while feeding himself a bottle of beer. It was oddly endearing, but still didn't stop the harshly whispered argument that followed as to the baby's owner and just what the mosshead thought he was doing.
Zoro adored children and was great with them. Sanji had always known that and been a mixture of jealous and awed.
Zoro was stubborn as hell.
Zoro was Luffy's de facto right hand and usually got his way.
Sanji knew it was all over when Zoro told the confused and concerned crew what he'd named the baby: Kuina. Knowing what they knew, it wasn't like any of them were heartless enough to keep fighting him on keeping her, not even Sanji himself.
The Straw Hat Pirates gained one new, adorable member that day, and have been sailing the seas with Kuina ever since. She and Zoro sleep in the previously unused captain's cabin and it seems like the marimo is prepared to take full responsibility for her care. Of course, he has 8 very enthusiastic crewmates who also want to dote on his baby, so Zoro does get frequent breaks from the whirlwind of unexpected parenthood.
Sanji is the only one who hasn't held her yet.
In spite of all of his initial complaining and reluctance to engage with the baby, Sanji still finds himself scouring all of his recipe books for the most nutritious and feasible formula options, plus starting a new notebook of plans for introducing Kuina to solid foods.
Time passes and soon enough, Kuina's first birthday comes. They don't know exactly when she was born, of course, but Chopper had estimated that she was less than 3 months old when Zoro found her. The crew had decided that the day she joined them was her birthday, and so a celebration was to be had.
Sanji still hasn't held her. In fact, he's never even touched her, not once in an entire year.
Kuina sits happily on her dad's lap, making a mess of herself and Zoro with the mini-cake that Sanji had so lovingly crafted for her. Her steel grey eyes, remarkably like Zoro's despite the lack of a blood relation, squeeze shut as she laughs and babbles to her smiling, cake-covered dad.
Sanji's heart clenches and he thinks maybe, maybe.
Her golden curls are soft under Sanji's hand as he passes by the pair of them on his way back to the kitchen.
