Sanji doesn't like owing anyone anything. He can cope with a genuine act of spontaneous kindness, the kind that happens just because someone is in the right place at the right time. He does those for people and so he doesn't mind having them happen to him so much. What Zoro did though was kindness when there was no reason for it. He'd been trying to drown the kelpy bastard and then when they struggled apart Sanji got smashed on the rocks, he deserved it for losing a fight with a human. And yet... Zoro did help him. Zoro took him ashore and got his nakama to patch him up and then he let him free back into the sea.
Sanji's ribs are almost completely healed, he'll still get a little twinge if he turns back on himself too sharply but other than that he's fine. All thanks to Zoro.
It seems that Zoro is a sailor of some kind, they're on a ship with a little sheep head on it. He's been following them at a lazy pace and he keeps catching Zoro peering over the edge of the ship for him now and then. Sanji's not entirely sure why he's still following Zoro. Is he really going to try to drown him again after Zoro helped him that much? He's not sure. Maybe. Certainly whenever he hears the bastard talk he has an inescapable urge to murder him.
He follows the ship underwater because, well, that's what he does now.
One night however the ship is beset by a monster of a storm. Even from Sanji's position a good twenty feet under the water it's buffeting him about and he can see that their little ship is struggling to stay afloat. He feels a sinking sensation in his heart, he can't see how their ship can survive this, he's seen amazing sailors and navigators drowned in less than this. Surprisingly their little vessel seems to be easing its way through the lightest parts of the storm, dodging the whirlpools and undercurrents. Sanji has no idea how they're doing it but he follows their ship, keeping a wary eye on the pitch and tilt of the vessel.
Sanji pops his head above the water and scans the ship, he can see Zoro in the rigging, plastered with rain and illuminated by flashes of lightning in the distance. He's trying to do something to keep the sail in place but Sanji can't see well enough to work out what he's doing and he's not knowledgeable enough about ships to guess. He gasps at the ship runs into the edge of a whirlpool and violently pitches to the side.
Zoro is highlighted in the air by a strike of lightning before he plummets down into the whirlpool. Sanji is back under the surface and racing towards where Zoro ought to be. It's hard to find him, the water is murky with displaced sand and silt and the currents are smacking Sanji to and fro as well. It's minutes until he manages to find the idiot and drag him to the surface.
Sanji thanks the spirit of the Otohimi that Zoro coughs out the lungful of water as soon as Sanji drags him into the air. The ship is spinning away and Sanji can't rescue anyone else if they fall over, he just has to hope that no one else has the same accident.
It's hard to swim whilst holding Zoro above the surface but he manages it, he has no idea where he's headed but he needs to get Zoro to shore. Slowly the sea bed rises up to meet him and within an hour he's dragged Zoro onto the beach of a small island and pulled him far up enough the sand that he's unlikely to get pulled out to sea again. Sanji leans up on his arms and looks down at Zoro's wet features, his gently closed eyes and slightly parted lips. He runs his hand along Zoro's hairline for a lingering moment.
"WAKE UP FUCKFACE!" Sanji yells and backhands him in a very judicious manner. Zoro's head snaps to the side and he groans unhappily.
"Move your feet you unworthy sack of meat, you need to start a fire or you'll freeze to death. I might be able to live in the cold ocean but you can't!" Sanji barks out.
Zoro sits up all dizzy and uncoordinated. He rubs his head and groans again.
"Chop chop brainless wonder! FIRE!" Sanji yells. In truth he's scared for Zoro and the only way that he can tell how to express that is through yelling at him to ensure he's going to be okay. It's good intentions at a loud volume.
Zoro moves into action in uncoordinated pieces, his legs stumbling in a way that makes Sanji wonder if the idiot has hit his head or something. By the time Zoro's got the materials together for a fire he's shaking so violently that he can't manage to light it. Sanji sighs and crawls up on the beach, leaving tail tracks in his wake. He takes the sticks from Zoro and imitates how he rubbed them together, he's never done this before, being a merman he's never had a lot of need for starting fires, perhaps he should carry a lighter with him if this is going to be a regular occurrence.
Zoro rests on his side and breathes shaky breaths out on the base of the stick. Soon enough smoke appears and then the beginnings of fire, at that point Zoro takes over, gently adding small pieces of debris to the pile until it's bigger. His trembling starts to subside as the warmth of the fire washes over him and Sanji relaxes bit by bit.
"Did you see anyone else fall out other than me?" Zoro asks, his voice slow and cold. His eyes don't leave the fire and Sanji isn't sure what answer Zoro wants to hear from him.
"I didn't but... I didn't stick around to see, I just grabbed you and got out of there." He answers warily.
Zoro moves fast. He slams Sanji back down on the beach and thank goodness he's flexible because his tail is bent double underneath him, Zoro's snarling face is inches from his own.
"WHY would you save ME when they were in danger?! My nakama needed help and you just took me?! WHY?!" Zoro roars at him.
He is clearly upset. Sanji punches him in the nose, flicks his tail out from under him and catches Zoro in between the legs with it. That'll help.
"I can only save one person, it was hard enough keeping you above the water, I couldn't do it with anyone else. Besides, it's not like I saw anyone else but you fall in, I didn't choose you above anyone else if that's what you're pissed about. And you're fucking WELCOME for me saving your worthless human life anyway!" Sanji snarls back at Zoro's crouched form.
"Why would you save me? You've been trying to kill me ever since I met you, you've been trying to drown me no less and the moment I stand a chance of drowning you save me? Why?" Zoro mutters, his hands clenched in the sand.
Huh. Good fucking question. Sanji doesn't have a true answer to hand so a bullshit made up on the spot one will have to do.
"I want to drown you, I don't want to just see you drown. It's a subtle but important difference." Sanji sniffs primly.
"Fine." the human says in a dead voice and turns back to face the fire, his arms wrapped around himself.
It's silent now and oppressively so. Sanji looks out into the ocean and thinks for a moment.
"If you stay here and keep warm I can go find your ship again. See if the others made it and find a way to bring you back there if they're still ok." Sanji offers quietly.
The human looks over at him, his eyes sad but grateful.
"Thank you." Is all he says.
"Ugh. Just... keep warm okay?" Sanji mutters and slides into the water, flipping and skimming quickly out to sea. He retraces his route easily enough, though he's turned around once or twice by avoiding whirlpools and the like. To his surprise when he reaches Zoro's ship it's upright and sitting innocently in clear blue skies and sunshine.
"We need to go back and find him!" Someone above shouts.
"I've no idea where or when we even lost him, I can't just get us back there like that!" A woman replies with an upset yell. Sanji's ears perk up at the female voice.
"We have to try Nami, you know he would for us!" Another voice chips in.
"OI!" Sanji shouts up from the sea. He slams his fist on the side of the ship a few times to get their attention. After a moment the face of the little reindeer who bandaged him up peers over the side.
"It's the merman! The one that Zoro's been fighting with!" The reindeer announces. Several other heads appear over the side.
"The name is Sanji." Sanji replies irritably, he's not his whole goddamn species after all.
"What, are you here to gloat about us losing him? You've been trying to drown him for ages now, you're probably over the moon." A red haired woman snarls at him, her eyes are filled with angry tears and Sanji's heart wrenches for her.
"No, he's fine. I dragged him ashore about an hour away, if you give me a boat I can bring him back here." Sanji answers instead. The expression of all of Zoro's crew lighten instantly, he must be well liked.
"Get a boat now, and some rope." The one with the hat orders. Sanji supposes that he must be in charge around here, funny, he thought it'd be Zoro in charge. Ah, well. This crew probably stands a better chance of living if that idiot isn't in command.
He waits patiently in the water whilst they lower a boat and some rope down. The furry one insists on filling the boat with warm clothes, waterproofs, water and food for Zoro and covering the entire thing in a tarp to keep it all safe. There's a rope threaded through the metal things for the oars, Sanji has no idea what they're called of course, he's never even been in a boat before. With the rope though he can swim under the boat and pull it along behind him without tipping the boat forwards.
"Isn't it going to be hard getting that boat through the storm to Zoro and then back again if you have to be on the surface?" The orange haired woman asks him nervously.
"It's certainly going to be harder than getting here was, I'd better get moving." Sanji sighs forlornly and settles the middle of the rope around his torso.
"Hey, thank you for this... you didn't have to." The girl says, touching his arm. Sanji shivers and blushes. He manages to mumble out something about how she's welcome and a beautiful lady like her should get all she desires, then before he can make a bigger fool out of himself he dives down and sets off back towards Zoro.
Good god he has no idea how humans survive in boats. Whenever the boat pitches and rolls it yanks him with it, even with his strength in the water the whole thing is frankly starting to make him a little motion sick. As if that crime against nature wasn't enough he's getting rope burn from every time the rope yanks at him. He has to give whirlpools a wide berth to avoid getting the boat sucked in and drenched.
It takes him three times as long to get back to Zoro as it did to get from him to the ship and Sanji is way more tired than he ought to be when he gets there. Zoro is already standing up on those legs that he doesn't even deserve and watching Sanji come in as he approaches the island. At least the bastard runs out into the sea and drags the boat off of Sanji and drags it to shore himself. As soon as he's done that he sprints back out into the water, splashing it everywhere and picks Sanji up bridal style, leaving his masculinity to wash away with the waves. Bastard.
"Your friends are all fine, you're the only one who took a drink in the sea. They sent this boat full of lots of heavy shit for you so I can bring you back." Sanji groans. Good god everything hurts.
"Are you okay? No offence but you look like shit." Zoro says, setting Sanji gently down on the beach.
"Well, I was going to be super offended there but since you said no offence, we're cool." Sanji sighs, his eyes shutting wearily.
"Oh really now?" Zoro teases him back with a grin. Sanji doesn't bother to respond and instead just slaps Zoro wetly with his fin and rolls face down on the beach to rest.
Zoro leaves him alone after that and instead goes to investigate the little rowboat and its contents. He takes a big swig of water and eats a little of the food. He strips off his newly wet clothes and starts to dry himself off with a towel.
Not that Sanji is watching of course. Never.
If he was watching he wouldn't be admiring Zoro's perfectly muscled ass that's for sure, he wouldn't be staring at the dimples in his lower back just above it or the way the muscle is leanly defined. His eyes wouldn't be running over Zoro's deliciously defined hamstrings as he bends over and kicks his way out of his black trousers. He certainly wouldn't be admiring how that sunkissed tan runs all over his body, not at all.
Sanji is face down in the sand by the time Zoro looks back at him in his clean change of clothes, it's the quickest way for him to quell his blush and think about his life choices and why he seems to be leering at a guy he's repeatedly attempted to drown.
"Hey, I've got food and drink here if you want it, you should have some too." Zoro offers him, crouching down next to him on the beach.
"Don't start, just... just get in the boat and then I can return you to your group and forget this day ever happened." Sanji grumbles, ushering Zoro to the small boat and sliding himself into the water and getting the rope around himself. The journey back is a little less tiring, the storm has mostly moved on a little and dissipated in places but by the time Sanji presses his palm against the hull of the boat he's thoroughly exhausted. He bobs under the surface and hears Zoro and the other humans talking to each other, he leans forward and rests his head on the wood. After this he's got to find somewhere to sleep and when he does he's pretty sure he'll sleep for about a million years.
A strong hand closes around his wrist and pulls him up above the surface, the difference in tension makes Sanji whine unhappily. Zoro peers down at him for a moment before yanking him up higher and then catching him under his arm.
"You saved my life, the least I can do is to get you up here to have a rest or to get you some attention for that rope burn." Zoro insists, climbing up the ladder on the side of the ship.
"I'll have a look at that Zoro! I want to see how his ribs have healed too!" the reindeer pipes up.
"Ugh, no. I'm fine. I'll just sleep it off. You helped me out with my ribs, I helped out out. We're even now and I can go back to trying to drown you, if you drag me up there then this whole stupid cycle will start again." Sanji protests, squirming weakly in Zoro's arms.
"God, then we might actually be nice to each other on a regular basis." Zoro remarks with mock horror, still climbing the ladder with Sanji under his arm.
"The horror." Sanji agrees with a weak grin.
Zoro puts him on the deck first and immediately the little reindeer is fussing over him, looking at the place on his chest where the rope rubbed and feeling up his old rib injuries. After that the guy with the hat on comes by and slaps him on the shoulder, thanking him for saving his nakama's life. In all honesty it's a bit of an exhaustion soaked blur. What he does remember though is Zoro putting him in a large bath and running it until it's almost overflowing, he remembers the way that Zoro's hand dipped under the water and carded through his hair. It's the last thing he feels before sleep overtakes him.
