The Broken Lock — One Piece
Summary: Luffy has too much fun being tickled for it to be used as a proper investigation tool, Sanji realizes that pretty quick. Luckily, he and everyone else knows of a straw hat that tickling works hilariously well on.
Warnings: Tickling
Other: Lee!Luffy, Lee!Usopp & Ler!Sanji from One Piece. 4k words. (All dynamics are platonic, but I’m a big Sanuso shipper so if theres vibes I apologize.)
A/N: This fic takes the record of being the longest tickle fic I’ve ever written HOLY. Sorry mizuena fic, your crown has been stolen. If you can’t tell I’m superrrr (franky reference) into one piece rn lmfaoooo. I really love these three, definitely my favourites along with Robin! Hope you enjoy, and I hope the characterization is okay!
“Luffy! Get in here, right now!” Yelled a voice from the kitchen, his shouts echoing throughout the deck as all the other straw hats turned their heads on reflex.
“Hah, Sanji sounds mad.” Zoro grinned, looking down at his captain who was suddenly looking very guilty— avoiding all possible eye contact with Chopper whom he was previously playing with. “What did you do this time?” The swordsman asked with a small laugh, Luffy reaching up to scratch at the back of his head.
“Meee? Hahaha, y’know—”
“LUFFY! If I don’t see you here in the next five minutes, you’re skipping dinner!” Sanji yelled one more time, interrupting his captain's weak words with an honest warning.
At the threat of no food, Luffy stood up almost instantly. For some reason, running towards Usopp who was currently lost in conversation with Nami. Usopp gasped when his captain suddenly grabbed his wrist with the intent of dragging him away. “H-Hey?! What are you doing?!” Usopp groaned, dragging his feet on the wood.
Luffy paused, the motion almost making Usopp slip face-first. “Come with me, please! I need the moral support to deal with Sanji’s yelling!” He begged with a small whine, something the boy did quite often when he wanted something, even though it hardly worked on his crewmates anymore. “Come on, with you around, maybe Sanji will go easy on me!”
Usopp looked at his captain's puppy dog eyes and sighed. “Urgh, fine! But you'd better protect me if I get caught in the crossfire!” He made Luffy promise with their pinkies connecting childishly, the two nodding in agreement before heading to the kitchen.
Usopp wasn’t sure what Luffy had done to make Sanji so mad, but surely, it wouldn’t hurt to be there as friendly support, or a mediator, right?
Well, that’s what he thought, until they entered the kitchen and Usopp spotted it, the fridge lock was completely shattered. His eyes widened as he quickly realized what had happened, his head whipping towards Luffy. “You dumbass! You didn’t..!” He whisper-yelled.
Basically… late last night when Usopp and Luffy were still up messing around, Luffy got hungry. When he went to the kitchen and came back with some food, Usopp just assumed Sanji was still awake in there and had whipped something up for their captain to eat.
Clearly— by the bent fridge, broken lock, and an angry Sanji emerging from the pantry, that was not the case.
Wait a second, is that why Luffy dragged him along?! To take some of the blame for HIS crime?! Oh, that stretchy bastard!
Luffy went to reply to Usopp with a similar whisper before Sanji slammed an empty container hard on the countertop. Making the two boys straighten up instantly, “Now, Luffy.” He began with an evident edge to his voice, Usopp already starting to sweat without his name even being mentioned.
Just then, as if amongst his rage Sanji had been too distracted to notice Usopp being in the room with them as well, his eyes that were filled with fire suddenly softened towards him.
“Oh, Usopp!” His eyebrows raised, surprised. “This doesn’t involve you, don’t worry. You hungry or something? How about you just sit down at the table and I’ll make you something..” his head slowly turned towards Luffy. “…After I deal with this one.”
Once again Usopp felt nervous even if Luffy was the one he was drilling. It was his tone that was making the sniper so squirmy. Yet… he greatly appreciated Sanji’s instant assumption of innocence, not to say he isn’t innocent though, cause he totally is!
“S-Sounds good to me!”
Luffy’s mouth went agape, already having been ditched by his supporter who was now sitting at the table anxiously twiddling his thumbs. “Sanjiiiii, I didn’t do anything!” He lied unconvincingly, rolling on his heels.
“Don’t even.” He disregarded Luffy’s lies, walking over to him. “I want you to look at two things.” He started, pointing towards the broken lock and then the empty container. “You, being the idiot you are, broke the god damn fridge lock, and even bent the fridge while you were at it!” He began to yell, Luffy avoiding eye contact in a way a dog does when they’re guilty.
“Now I’m not stupid, you clearly took something from the fridge.” He then walked over to the container, holding the evidence up. “The problem is, I have no idea what was in here! So I don’t know if I have to remake something I meal prepped— or add something to the shopping list!” Sanji then walked back to Luffy, putting a hand on his shoulder. “I need you to tell me exactly what you stole right now, and then, you’ll be dealt with.”
D-Dealt with?! Damn, Usopp was now extremely happy to be safe at the table! Well, guess it can’t be helped huh? All Luffy can do now is fess up to Sanji, and pray the cook goes easy on him, then, things can go back to the chaotic normal it usually is.
Luffy, will definitely just admit it, right? He won’t be the stubborn idiot he usually is… right—
“I have no idea what you’re talking about!” Luffy avoided him with mock innocence, making Sanji almost throw the container at his face.
Oh. My. God.
Usopp almost face-palmed right then and there, how does this guy always manage to make things worse for himself? Why is he being stubborn?!
“The hell?! Luffy, I'm not an idiot! You’re the only person who could have done this!” Sanji said, growing fairly frustrated with his captain's actions.
“Um, nope. Wasn’t me, sorry.” He whistled, not even flinching when Sanji’s grip on his shoulder tightened a concerning amount.
The cook was losing his cool, and he had every right to be! Maybe Luffy just doesn’t want to face the consequences, but it’s obvious that he is the culprit. No amount of denial can change that fact. “Fine, if that’s how you wanna play? I’ll play.” Sanji grumbled.
Seeing Sanji become so angry in the corner of his eye, made Usopp debate admitting what Luffy ate for him, I mean— he does know after all. It’d be nice to get this situation over with, Sanji’s wrath should never be underestimated. From past experiences, Usopp knew that well.
And yet, that consideration was lost when sudden screams of laughter filled the room and stole Usopp’s attention. A sound you would never expect from such a tense situation— but it rang clear.
He looked over to see what was happening, no more of those sneaky side glances. There was no denying what he saw, or heard— Sanji had latched his hands onto both of Luffy’s hips, and was squeezing at them relentlessly. Luffy, bursting out with surprised laughter.
“Hehehehey! Sahahahanjiiiii!” Luffy giggled, curling forward as his hands wrapped around his waist.
Sanji’s smirk was almost devious. “What? You asked for this. This is your punishment for being so stubborn.” The chef explained. This unexpected turn of events making Usopp’s eyes widen. “You admit what you ate, and apologize for breaking the fridge lock, and I’ll spare you. How does that sound, Captain?”
“Dohohoho yohohour wohohorst!” Luffy challenged cheerfully, not at all shaken by Sanji’s attack. If anything, he looked happy.
Sanji though took that as an invitation, tackling him to the ground and hovering over him. The blonde wasted no time, his hands finding their way to Luffy’s waist, targeting any spot that Luffy wasn’t rushing to defend with his arms.
The banging, clashing, and loud laughter made Usopp jump, unsure on what to do in this situation. Should he… leave? Would that look suspicious or unnatural? He didn’t know, but he sure as hell couldn’t focus on finding the right thing to do with Sanji’s teasing words to Luffy distracting him like crazy.
“Such a high bounty, when all it takes is a couple of tickles to take you down? You’re no threat at all.” Sanji commented, his expression smug.
Luffy was squirming so much that he was practically rolling around, making Sanji’s hands basically chase him. “Sahahays yohohou!” He snapped back, completely unbothered by Sanji’s attempt to fluster him.
That in return made Sanji’s cheeks burn a slight red, probably because Luffy was right. Still, a little bit of an annoyed growl was added to his voice. “Why are you being so difficult? Is it that hard to just admit it?! I seriously can't with you!” His voice came out as a whine, his frown coming back.
“Sohohohorry Sahahanji!” He apologized mindlessly for those critiques, not caring in the slightest.
Usopp had his head kept down, deciding it was better to pretend he wasn’t even here. Sanji on the other hand continued his attack, working at making Luffy’s laughter grow in volume and rise in franticness. Despite those changes, Sanji would be a fool not to notice that his laughter, his smile, and his eyes, were still so god damn happy.
Not that Sanji wanted him to be sad or anything— but he was clearly enjoying being tickled like this! With such a playful means of interrogation, he’d prefer Luffy to enjoy the laughter but still want to cave. Yet, that outcome didn’t seem the slightest bit plausible now.
And unfortunately, even if Sanji had his sights set on figuring out what his captain stole…. And hated how stubborn he was acting—
He found Luffy’s joy to be annoyingly adorable. Why did his captain have to be so cute? He cursed how his frown was rapidly dissipating.
As he looked down at his giggling friend, Sanji finally cracked. Failing to hold back an adoring look, a fond smile finding its way to his lips. “This is pointless, hmm?” Sanji noted, shaking his head with a small laugh. “This isn’t a punishment for you at all, is it Luffy?” He complained despite speaking so sweetly, analyzing Luffy’s genuine joy at this situation.
Luffy’s arms hugged his tummy, laughing loudly without a care in the world. “Why wohohould it behehehe?!” He questioned cheerfully, lost on why this could be considered anything other than innocent play between two friends.
Sanji rolled his eyes lovingly. Jeez… his captain was definitely having fun. “You’re hopeless.” He sighed, his fingers climbing their way up and digging into the grooves of his ribs, Luffy’s arms clamping tightly against his sides as a reflex.
He was laughing like crazy, but still had the happiest expression ever, it was making Sanji lighten up more and more. “Thihihis ihihis fuhuhun!” He squeaked.
Sanji unfortunately felt his heart warm at such an adorable admittance, rolling his eyes again. “Damn it, stop being cute, I'm supposed to be mad at you.” The chef joked a bit, Luffy kicking his legs.
This clearly wasn’t working, but Sanji still needed to know what Luffy ate, so evidently… the chef needed to somehow find another way of getting some answers.
He looked around the room hoping for inspiration to strike him, only to find Usopp avoiding all eye contact with them, which was odd. Usually, he’d be watching such a playful dispute with a smile, giggling quietly at the silliness of it all.
Though Sanji had let him off the hook earlier, telling him to sit down and assuming he came in for food— now that he was looking at him more intently, his body language read nervous. It was clearly Luffy who did this, so why did Usopp look so guilty?
A light bulb instantly lit up in Sanji’s head, a devilish grin taking form. He wasn’t sure of the exact context, but he totally knows something, doesn’t he?
Still making Luffy laugh like a madman, he focused his gaze completely on Usopp. “Now, it’s obvious tickling won’t get our dear Captain to fess up…” Sanji announced loud enough to make Usopp jump at his volume, a sight that made Sanji snicker. “Our ticklish little sniper, on the other hand…”
Those words made Usopp completely panic, his head turning around slowly, in an almost cartoonish way. “W-What did you say…?” He asked, struggling to wipe a nervous smile away. “M-Me?! Why would you target me? I-I don’t know anything!” He stuttered over his lies, shrinking when Sanji’s eyes sparked an impish gleam.
That's when their Captain suddenly burst out with a silly warning. “Usohohohopp! Sahahave yohohoursehehelf! He knohohohows!” Luffy squeaked out with bright giggles, the sniper's eyes widening instantly.
“L-Luffy!” He scolded, cursing his captain for completely ruining his chances of lying his way out of this. Well, not that the chances were that big anyway, but still!
Everything was tumbling downhill! Usopp really thought he’d be safe if he just played dumb and waited for everything to be over, how could he be so naive?!
In a flash, Sanji stood up and left the melted puddle that was now Luffy recovering on the ground, eyes locked on to the wide-eyed sniper. Usopp scrambled out of his seat, unable to control the butterflies that started swarming in his tummy.
One step forward, and this advancement quickly turned into a playful chase between the two, the pair running aimlessly around the kitchen. “Nononono! Stay b-back! This isn’t fairrrr!” Usopp whined, all while smiling like an idiot. “How did you even— how did you figure out that I know?!”
Usopp had yelled at Sanji while jumping behind their island, Sanji running up to the other side still grinning. “You couldn’t have been more obvious, Usopp. For such a good liar, you can’t keep secrets for shit.” He teased a bit, even if he was telling the truth.
The truth didn’t help Usopp’s impending doom, though, nor did it stop the giddy titters that were now slipping past his lips. “Sanji— plehehease! C-Can we tahahalk about this?!” Usopp pleaded, being circled around the island tauntingly by Sanji.
“The only talking I want is your admittance.” The chef said with a mischievous smirk, suddenly leaping over the counter and grabbing onto Usopp.
Usopp screamed as this happened, absolutely helpless as Sanji with ease led him softly to the ground, straddling his hips with his powerful legs, all while Usopp giggled madly and pleaded some more with the blonde.
His pleas fell on deaf ears, as Sanji after getting properly situated dove for Usopp’s sides, scribbling at the sensitive skin in a way that he knew worked well on the boy.
Usopp failed miserably at holding back his now pouring laughter, latching onto Sanji’s wrists as weak hands tried to push the cruel and oh so evil tickles away.
“EEEAHhahahaha! Sahahahanji! Eeeheheek! Nohohohoooo..!” He squeaked and squirmed as much as he could, his face split into the most adorable smile, one that made Sanji’s just as wide.
“Dohohon’t tell him ahahanything..!” Luffy called out tiredly.
Hearing that, Sanji moved his fingers towards his tummy, clawing at the spot just above his belly button. “Ignore him Usopp, you’re too ticklish for this, yeah?” He snickered, enjoying making these teasy comments towards him.
Why? Because unlike with Luffy, it worked absolute wonders on Usopp, and garnered just the type of reactions Sanji wanted.
He immediately cackled at both his words and the tummy tickles, shaking his head frantically back and forth. “Luhuhuffy! Sahahave me!”
The straw hat stayed still, sprawled out on the kitchen floor, his chest moving slowly up and down. “Suhuhure… lehehet me juhuhust… catch my breheheath..”
“LUHUhuhuffy!” He screeched, not only was he getting caught in the crossfires as he feared— but Luffy was too tired right now to fulfill his promise of protecting him!
“Don’t worry, you can save yourself Usopp, just tell me what he stole!” Sanji urged, his clawing transitioning into a barrage of pokes across his tummy. “I could make this soo much worse for you. Don’t forget, I know all of your ticklish spots!” Sanji threatened playfully, giggling sweetly at how it made Usopp flush a bright red.
For being so angry earlier, he sure did sound pretty damn cheery while reducing Usopp to a sputtering, laughing mess. “And I mean, all of them.”
With that, Sanji’s fingers reached behind him where Usopp couldn’t see, squeezing at his calf muscles gently, Sanji’s thumb and fingers nipping at the spot repeatedly. “PFFAHAHAHAHA! NaHAHAHhahat thehehere!” Usopp screamed, his legs kicking a lot more wildly now— it was a miracle that they hadn’t hit Sanji in the face yet.
How embarrassing, Sanji really did know all of his weak points. In all honesty, Usopp had forgotten just how ticklish his calves were, but with how lost he was in his current laughter? He was sure he’d never forget again.
Head tipped back, he felt his tummy becoming a bit sore from all his laughing. They really give the toughest battles to the most ticklish of people, huh?
Unfortunately for Luffy, Usopp was not his strongest soldier. “Thahahat’s ihihit! I’m tehehehelling him— Ihihim tehehelling hihihimm!” He caved, announcing it loudly and letting the exhausted Luffy know that betrayal was just around the corner.
Sanji beamed with pride, he knew this would work! Thank you Usopp for being so ticklish, he thought. It really made things easier for him. “Attaboy.” Sanji praised, removing his fingers from his calves and reaching a hand forward to gently rub Ussop’s arm. Being kind enough to let the sniper somewhat catch his breath.
His chest rose and lowered, taking in selfish gulps of air that were often interrupted by aftermath giggles. After a couple of seconds, Usopp was able to open his eyes, looking towards Sanji. “Ohohokay.. okahahay.” He started, letting out a shaky sigh. “Basically— me and Luhuhuffy were—”
Just then, the truth was interrupted by Luffy who lunged forward towards the pair. Making it clear he had finally recovered from earlier by the speed of his movements. What followed, was an instant return of Usopp’s laughter, Sanji watching the whole thing with a raised brow.
“W-WHA?! Luhuhuffy?! Whahahat thehehe hehehell?!” Usopp gasped when Luffy’s fingers hooked under his jaw, digging under his chin and scribbling against his neck. Naturally, the sniper was confused, but also very distracted by the feeling of one of his worst spots being targeted, scrunching up his shoulders desperately.
Luffy’s eyes narrowed, staring down at his sniper. “Don’t you dare Usopp!” Shouted his captain, “If you tell him, I’ll never stop tickling you!” The boy warned, still fluttering his fingers against Usopp’s neck.
The sniper was appalled by his threat! It was childish, and unfair, yet he couldn’t do anything about it. Usopp squealed as the tickling continued, he didn’t know who to call for help at this point. Luffy was supposed to protect him, but now, he’s the one tickling him!
Sanji listened to that whole exchange of theirs and burst out into giggles at the absurdity, his captain really was something else. Unfortunately for Luffy though, his final attempt at saving face became fruitless when Sanji grabbed him by his shoulders and threw him next to Usopp, freeing the sniper from his tickles.
“Nice try, Captain.” Sanji grinned before both of his hands shot under Luffy’s arms, surprising no one when loud boyish laughter followed suit. Once again Luffy was laughing under the hands of Sanji, and he totally deserved it. “Now Usopp, as you were saying?”
“Dohohon’t! I behehelieheheve in yohohou!” His captain wailed, his supportive words not meaning shit after that stunt he pulled.
And yet… “I-I...” Usopp hesitated, he wasn’t sure why. He was pretty eager to tell the cook everything before, but something now told him to stay quiet.
Sanji took quick note of this silence, a hand leaving Luffy to lift Usopp’s shirt. That specific movement made a fluttery knot grow in Usopp’s stomach, especially when he heard Sanji take in a deep, deep breath of air.
“AHhaha wait nonono! Sanji— dohohon’t! I’ll tahahalk! I’ll talk!” He folded like earlier, pushing at Sanji’s face that was now hovering over his exposed tummy. And just like that… one threat of raspberries and Usopp was back to compliance.
Sanji blew out that stored breath, feeling just a little bit disappointed he didn’t get to blow a raspberry on Usopp’s tummy and watch the boy really laugh. Well, this was a win either way. “Good choice, Usopp.” He said, reeling back as his other hand returned to Luffy. Paying little to no mind to how much the stretchy boy was laughing and squealing, more focused on Usopp.
When Usopp started to talk, Luffy yelled at him with more giggly threats. “Bahahasically, me and Luffy were up late last night— he went to get a snack, and when he cahahame back, he had this squid dish, I don’t knohohow what it was!” He started to explain, Sanji nodding along.
“Ah, so that was it. You ate the squid risotto meal I prepped, huh? You’re lucky I still have squid and can remake it, you little shit.” Sanji glared down at Luffy. Though, noticeably with zero anger in his eyes much like earlier, his gaze still shining with playfulness rather than rage.
“I-I promise thohohough! I had no idea he stole it! Ussop’s word!” He swore, glad he didn’t need to lie in his explanation.
“Yeah, yeah. Don’t worry, I believe you.” Sanji sighed, taking in his admittance and analyzing the situation quickly in his brain. A couple of seconds later, his fingers stilled, sparing Luffy.
He looked down at both boys, his knees that were still straddling a tuckered-out Usopp, and Luffy who was curled up in an even more tuckered-out ball. They both looked tired, yet happy? That was good, he knew tickling wasn’t something negative for Usopp either, no matter how effective it is on him.
With a comforting pat on Luffy’s back from Sanji, and two gentle kisses placed on top of their foreheads, the cook started to stand up, leaving the duo to continue lying on the ground. “Well, I'd better get to cooking, then,” Sanji said, going to the broken lock.
Luffy, and Usopp both felt a bit… shocked by his words. Though they were too tired to move, their eyes locked onto Sanji who seemed very calm. Was Luffy really getting off that easily? No punishment, nothing?
Luffy wanted to question that. “Aren’t yohohou gohohonna… d-deal with mehehe?” He enquired through aftermath giggles, still feeling the warmth of that gentle kiss Sanji had placed on his head.
“I think I just did, didn’t I?” The cook amused, curling his fingers in the air as emphasis. Sanji found himself holding back a laugh when that tiny motion made both of them visually tense up— despite knowing they were safe from more tickling.
Luffy let out a sigh of relief, his smile widening. “Though, you did cause quite a lot of damage…” He pondered, looking between him and the broken lock. “Once you’ve calmed down, how about you go fishing for me? Catch me something good, and I’ll consider your debt paid.”
The captain sprang up, having enough strength to sit up and shoot Sanji a proud grin. “I can do that…! I’ll catch you the biggest fish ever…!” He cheered, just a little out of breath.
That sounded good to the chef, humming a satisfied sound.
Luffy after a couple more minutes of catching his breath stood up, reaching a hand towards Usopp who had one eye closed. “Come on, let’s go catch a fish together!” He urged, flashing his signature wide-toothed grin.
“Yeah…! Let's!” Usopp nodded, taking his hand and letting himself be dragged upwards, Luffy lifting his friend’s weight with ease.
When they began walking out the door, Luffy slung an arm around Usopp’s shoulder, leaning in close and complaining in his ear. “I can’t believe you told on me, you snitch.” He joked a bit, making it obvious that he wasn’t genuinely mad at him for folding.
Usopp deadpanned, shoving him light-heartedly, “Don’t even with me, or you can catch this fish on your own.” He warned playfully, sending a quick poke to Luffy’s side.
One, that the captain returned instantly. The pair laughed together as they headed back out to the deck. Sanji, left cooking with a satisfied smile.

















