Seulgi’s day started out weird as it is. She exited out of the Hufflepuff common room expecting her best friend Wendy to be there but was instead surprised to see her gryffindor friend, Irene, who rambled on about her sister Yeri and their Slytherin friend Joy kidnapping her said best friend.

“Must be one of their shenanigans again.” was all the older girl said before pulling the poor confused bear to go to Hogsmeade.

Seulgi didn’t get to see nor hear anything about Wendy the whole day up until the time Yeri nervously pulled her aside and asked her to go with her because she thinks she lost something by the fifth floor prefects bathroom. They entered the bathroom and there was immediate utter silence as Seulgi stopped in her tracks and stared upon the filled bathtub, Joy smiling nervously at her and her best friend’s eyes staring right into hers.

“So.. the thing you said you lost...” she paused, looking at the youngest with fierce eyes, “It was Seungwan’s legs?!!!!!” the last part came out shrill as Seulgi almost tripped and fell trying to get to her best friend.

“PLEASE DON’T TELL UNNIE!!!” Joy pleaded and the bear just glared at her which made her shut up.

“Wendy, what did those two do to you!” Wendy looked up with teary eyes and opened to speak but a shrill scream was all that came out. Seulgi and the other two immediately put their hands on their ears and winced. The ravenclaw girl gave a sob before turning away and sinking herself down on the tub.

“Everytime unnie speaks, it just comes out as that.” Yeri explained.

“What the hell did you even do to her?!”

“Uhmm, okay so don’t be mad--” Joy started.

“Too late for that.” Seulgi glared some more.

“Anywayyyyy, Yeri and I were doing some research with potions and charms and we thought we asked Wendy unnie since she’s top of all her classes and then YERI TRIPPED OVER AND EVERYTHING SPILLED ON WENDY UNNIE AND--””

“YAH UNNIE! YOU WERE THE ONE WHO PLACED YOUR STUPID ROBE AT WHERE I WAS WALKING AND CARRYING THE STUPID CAULDRON YOU LEFT AND--” the two younger girls began shouting at each other. Seulgi groaned before reaching out to her best friend, the white hogwarts polo uniform clinging onto Wendy’s body and the gray skirt floating along with the fishtail that the latter now adorns.

Wendy’s eyes are still teary, she tried wiping it with her now webbed hands which everytime she notices only made her tear up some more.

“Wan, we’ll fix this, I promise!” Seulgi whispered loud enough for the younger one to hear before turning to the two still bickering girls, “Get Irene unnie.” that seems to halt the shouting match of the two.

“BUT—“ The bear like one glared so sharply Joy swore she felt the hair on her whole body rise.

“O-o-okay” Joy stuttered, giving Yeri a slap on the head to follow her.

It took a while before the younger girls came back with their oldest unnie, mostly because Irene was skeptic about her two dongsaengs suddenly smiling all sweetly at her while asking her to go with them--which always mean they did something naughty--and by the look of the tail sprouting out from the waist of her ravenclaw friend, she’s very sure that it’s the two’s antics again.

“What did you do now?” She glared at the two.

“IT WAS JOY UNNIE’S FAULT!”

“YAH!!!” Irene rolled her eyes at the two idiots.

“Seul?”

“I think I know how to talk to Wendy.”

“Wha--” and before anyone can stop her, the bear already plunged her head on the bath tub, sticking up in the air and motioning for Wendy to do the same  which made the youngest two burst into laughter but was immediately shut up by the icy glare that the oldest has given them. It took a few more seconds before Seulgi, now half-drenched, grinned in triumph.

“I can understand her!” Irene worriedly stared at her friend who just plunged her head again under the water excitedly. She sighed and glared at the two youngest again.

“Get me all the books you can get about mermaids and transfiguration.” She ordered the two who saluted, “I’ll go get some gillyweed.” and with that, the three of them were scurrying out of the bathroom.

They came back a few hours later, the two youngest followed by dozens of floating books from basic to advanced theories. They waved their wands and the books landed with a thud across the tiled floors. Joy looked towards the two older ones who were by the corner with Seulgi smiling gently and whispering to Wendy while holding out the latter’s webbed hand.

“Stop staring” Yeri whispered, elbowing her in the process.

“What do you think they’re talking about?” She whispered-asked, sitting down and opening a book to start researching.

“Beats me” Yeri shrugged, stealing a glance before going back to reading, feeling like she’s intruding something intimate. Irene came back a few minutes after, gillyweed in one hand and a paper bag on the other.

“Hey, Seul! Here you go” the oldest handed both things to the bear like girl who took the paper bag and opened it with a confused face.

“A swimsuit…?”

“Yeah. Change first before you eat the gillyweed. Figured you should ask Wendy what those other two placed in the cauldron, maybe we can reverse the effects.” Seulgi nodded, mumbling a ‘just a sec’ to Wendy before standing up and going to one of the cubicles to change. She came out a few minutes later clad in a gryffindor colored swimsuit and Joy had wolf-whistled at her before Irene smacked the taller one.

“You look good in red, unnie!” Yeri gave a thumbs up which made Seulgi’s cheeks tinge pink.

“Thanks...” she mumbled, getting the gillyweed and looking at it hesitantly before placing it in . She made a face before she felt a prickly sensation on her neck and suddenly it was getting harder to breathe.

“Go in the water!” Irene ordered in panic and Seulgi stumbled towards the bathtub,falling ungracefully with a splash. The oldest sighed, motioning for the younger two to hurry with the research.

She can feel the water wade through her neck that’s now adorned with gills. It was warmer than she expected it to be. She slowly opened her eyes and was met with those warm brown ones that she oh-so-adores.

“Seul..?” the smooth warm voice of her bestfriend called out. She opened and closed it again in shock, before she realizes that she’s breathing under water.

“Wannie!!!” She swam towards her mermaid of a bestfriend, reaching out and holding her hands. The latter smiled half-heartedly which made Seulgi worry some more. “Don’t worry Wannie, we’ll fix this! Can you tell me what’s in the potion ingredients that those two evil spawns of satans were trying to make?”

“I..I don’t know” the younger one looked away, taking her hands from Seulgi’s grip and crossing them on her chest. The bear’s brows furrowed at the action, moving forward as Wendy floated away.

“He-”

“All I remember was those two snickering before Yeri stood up and slipped carrying the cauldron.” Wendy’s back was now turned towards Seulgi and the latter doesn’t know what to do. They were enveloped in silence, the deafening sound doubled by the water.

“Hey...” Seulgi reached out after a while, swimming in front of the younger one who was looking down at her webbed hands. Wendy’s eyes glanced up, meeting the older one’s eyes before moving down and staring at the red swimsuit, the gryffindor emblem shining through the waters. Wendy huffed and rolled her eyes before turning away from Seulgi again which only made the latter’s face turn into despair.

“Wannieee~~~ what’s wrong?~~” The mermaid turned around, eyes glowing bright blue and Seulgi had gulped in fear.

“Unnie, look! It says here that mermaids are possessive and jealous creatures… you don’t think Wendy unnie...” Yeri’s voice died down as she chanced a glance at the bathtub before looking back to her two unnies.

“Gotta find that reversing spell or potion fast then” Joy mumbled, continuing to read-through the books.

“Remember that story about the mermaid who turned into human?” Irene suddenly asked.

“Yeah, what about that?”

“You know how fables are not really fables when it comes to the wizarding world?” Irene started.

“...oh”

“I mean, those two are obviously in love with each other...” Yeri mumbled which earned a nod from the two.

“W-wendy, what is it?” Seulgi asked, staring straight at the bright blue eyes of her friend. The latter huffed and glared. The bear followed the mermaid’s line of vision, “Uhm… do you not like red…...” Wendy’s eyes glowed some more.

“I don’t like you wearing that.”

“Huh?” Seulgi asked stupidly. Wendy glared some more and swam towards the bear, stopping just a few inches.

“I don’t like you wearing that.” she poked Seulgi’s chest.

“You don’t like me wearing red?” Seulgi tilted her head to the side in question.

“I don’t like you wearing something from another person!”

“But… it’s just Irene unnie’s~” Wendy glared some more and something inside Seulgi’s slow brain clicked, “Wannie, are you… jealous?” Wendy huffed some more and Seul has smiled gently before taking Wendy’s hand.

“No!” the latter tried to pull away but Seulgi held on firmly.

“Look at me, Wan~” she waited for the younger one to do so and when she finally did, Seulgi continued, “Irene unnie just lent it to me in my best interest but it doesn’t mean anything.”

“You don’t look good in red” Wendy mumbled.

“Then what do you think I look good in?” Seulgi asked, a small smile playing on her lips. Wendy kept quiet and the bear chuckled, pulling the smaller one and quickly wrapping her arms around Wendy’s neck, their faces a few inches apart. “Okay then, you know what I think?”

“What?” Wendy’s bright blue eyes have now dimmed down and there was a swirl of her warm browns underneath as she stared at Seul.

“I think...” Seul smiled, leaning forward and whispering, “I look good in blue.”

“We better--ahh!!” Joy stumbled backwards, she was running towards the bathtub when the two heads of her friends suddenly popped up. She placed her hands on her heart as she stared wide-eyed at the older ones who were now getting out of the tub with Seulgi helping Wendy out--the latter now tail-less.

“WENDY!”

“UNNIE!” The rest shouted together as Wendy wobbled a bit and Seulgi quickly placing her arm around the younger one’s waist to stable her.

“HOW DID YOUR LEGS COME BACK?!!!” Joy asked after composing herself. The two girls looked at each other then looked away quickly, cheeks tinged a bit red.

“Uhm, we were just talking about how the whole thing happened and..” Seulgi paused, ears and cheeks looking more and more like a tomato.

“And suddenly I have legs!” Wendy finished quickly, her face feeling a bit warm.

“Anyway, I better get Wendy back to the Ravenclaw tower so she can dry up and get changed quickly” Seulgi rambled, already half-way out of the prefects bathroom, leaving the three stunned girls gaping at them.

“Uhm… should we tell them that we know how to reverse the thing or...” Yeri asked.

“.....better not...” Joy answered.

“I guess they kissed.” Irene smiled, “finally.”

A/N: Hello hello!! 
This is probably the last oneshot from my pile of drafts from way back! I'm so glad I finally finished it! On to new ideas for oneshots then! If you have any prompts just hmu or something and I'll try my best to write them ^^

If you also happen to love bp's Chaennie, you can check out my other oneshot collection about them

Till next story!