Here is one of my contributions to SanNami Week 2017. This one is for Day 5 Prompt: Underwear.
Laundry Day, near the bench on the lawn deck… How did Nami get stuck folding everyone's clean clothes? Although she would never state it, she was assigned to folding duty for the whole crew after failing to put away her own clothes. Robin had warned the navigator that if her clothes were not put away within a week, she would be responsible for folding all of the Straw Hats' laundry the next time it was done. It wasn't the ginger's fault that she forgot… At least that's what she told herself.
One odd quirk to the daunting task was seeing the various undergarments belonging to the crew. Robin's black lace lingerie made Nami blush. I wonder if I'm mature enough to look good in black lace? Franky's various speedos made the navigator cringe. Why doesn't he wear pants?! Of course Brook and Chopper didn't really wear any underwear. That was no surprise. But nothing could have prepared her for the shock that came after folding some of Sanji-kun's dress shirts.
At first it looked like some sort of red headband. The article mostly consisted of strips of fabric much too small to be any sort of actual clothing. The cook never wore a headband though. After turning it a few times, Nami finally realized what it was. "A thong?!" she screamed as she practically threw the undergarment away from her. S-Sanji-kun wouldn't wear thongs, would he? Even the navigator rarely wore thongs. They were too uncomfortable. It didn't seem like a garment that men would usually wear. Yet, when she looked down, she found more in white, indigo, dark green… They were too large and plain to be Robin's. The cook's dress shirts had been in the pile on top of them, so…
"Ugh…" A wave of dizziness hit the ginger. Sanji-kun wore thongs. She didn't want to believe it. No matter how ridiculous his heart-eyed behavior was, Nami would never insult his fashion sense. Out of the male crewmembers, he was the most stylish. Discovering that he wore thongs just made him seem like even more of a pervert than Franky and Brook combined. "I feel sick," she mumbled.
"Nami-swaa〜n!" She heard the voice approaching her from behind. A creepy shiver caused the hair on the back of her neck to stand on end. "Robin-chan told me that I shouldn't offer, but I came to see if you needed any help!" The blond looked over her shoulder and froze. "Nami-san," his voice was dead serious. "Those…" Oh no! The navigator closed her eyes. Now he knows that I know. "Are they… yours?"
What?! Brown eyes jerked open. "What do mean are they mine?!" she lectured the cook. "Like I would ever wear something as ugly as these… There is no shape to them! They're not cute at all!" Then she paused. He was asking if they belonged to her? "You mean," she spoke in disbelief. "They're not yours, Sanji-kun?"
The blond stared at her. "Mine?! Why the hell would I ever wear a thong?!" He was aghast. "I would have to be an even bigger pervert than Franky to wear a thong!"
The navigator breathed a sigh of relief. Thank goodness. Sanji-kun was still stylish. "Then who…?"
"Ah, good timing! My fundoshi are clean." Nami and Sanji both silently watched as Zoro came to collect the undergarments. "I was afraid I would have to go without underwear today." The cook was about to yell at the Marimo when light blue lace was tossed at him. "I don't know how these got in there."
"Z-Zoro, you wear thongs?!" The navigator asked in disbelief. Why would someone so masculine wear a thong?
"They're not thongs!" The swordsman made no effort to hide his annoyance. "All of the men in my village wear fundoshi! Isn't it the same in most places?" Nami could only shake her head and shrug. She wasn't a man and she did feel like discussing various types of men's underwear. "Well, whatever," Zoro grumbled. "Thanks for washing them anyways."
With that, the swordsman left. The navigator turned back to her blond crewmate. "That was odd wasn't it, Sanji-ku…" She couldn't finish her sentence.
The cook had a deep red flush in his cheeks as he gazed at the delicate light blue lace fabric in his hands. He couldn't believe his good fortune. "Nami-san," his voice was soft with awe. "Are these…?"
Unfortunately, his good luck was short lived when he was met with a fist square in the face. Nami grabbed the panties with her left hand as the blond fell backwards. "Next time you see these it'll be 100,000 beli, Sanji-kun!" Turning her back to him, she quickly glanced over her shoulder and added, "Or at least dinner first." Then she walked away before the cook exploded in a flurry of hearts.
Fundoshi is the traditional Japanese undergarment for men.