Once upon a time, there was a beautiful mermaid who lived under the sea. With long red hair and a gentle demeanor, she was most proud of her captivating voice. Her name was-

"Riko-chan! It's Riko-chan!" cried Chika.

"What?! No!" denied Riko, fully knowing where this was going. "Ah, that is... I really don't need to be in this story," she said sheepishly.

"Yes you do," grinned You. "And I can't think of a more perfect role!"

"But-!" Riko cut herself off with a sigh. "I guess there's no getting out of this, is there?"

""Nope!"" chorused Chika and You.

...Yes. The mermaid's name was Riko.

And Riko was a dutiful and diligent little mermaid. She did everything she could to ensure the sea was as pristine and perfect as it could be, even doing her best to pick up after the humans that dropped things into the waters.

But she still held a fascination for the world above, and one day she got a first true taste of the world above when a human fall overboard and into her realm. Staring into the unconscious face of what was undoubtedly a princess, Riko became fascinated.

"It's Chika-chan!" interrupted You.

"What?! What do you mean? I'm not a princess!" exclaimed the ginger.

"Yes you are," asserted You. "You are absolutely the princess of the story."

"I can agree with that," said Riko with a small smile.

...Indeed, the princess's name was Chika.

Riko knew this human didn't belong underwater, and so returned her to the shore, singing to her all the while. And so Chika awoke on the beach, wondering just who had saved her from the dreadful incident that had sent her overboard, always returning to that very beach in hopes that her savior would be there, singing that beautiful song once again.

Riko watched from a distance, becoming more and more enamored with her human princess. Eventually, she decided she wanted to be human too. So she went to a fellow sea dweller, a sea witch of great power and fortitude.

"Hey, that sounds like You-chan!" chirped Chika.

"You think I'm a witch?!" startled You.

"I mean, power and fortitude? That's You-chan to a T!"

...Yes, the sea witch You. That was who Riko went to. Riko begged You to make her human so she could chase her beloved princess. You was willing to grant the request, but for a price. In exchange for giving her legs and lungs, You required Riko's beautiful voice.

"Why would You-chan force Riko-chan to give up her voice?" questioned the ginger.

"Maybe because she's also in love with Chikacchi and is jealous?" suggested Mari slyly.

"I dunno," added Kanan, "I think she just wants to keep Riko-chan's beautiful voice all to herself."

"What fascinating theories," deadpanned Dia.

And so Riko went up to the surface world to meet her princess charming. They met and got along quite well, but Riko could not speak to tell Chika she was her savior. Eventually, it came time for the princess to choose a bride, and so she held a competition to see who could impress her the most. When the day came, Riko wondered just how she would impress the princess, but her heart stopped as she saw that her competition was her fellow sea dweller You!

"You-chan, how could you do that to Riko-chan?" gasped Chika.

The brunette grinned. "I'm a witch, baby! It's what I do!"

You gave a spectacular performance with her own beautiful voice, wowing everyone in attendance, including Riko.

But Riko refused to give up. In front of Chika and You, she used her natural talents and played a hauntingly moving sonata on a piano. Not only was Chika charmed, but so was You, and the sea witch returned Riko's voice to her freely.

And so enchanted were they with Riko that the three of them lived together as humans, happily ever after. The End.

"Oh, oh!" interrupted Chika with a grin. "Can You-chan and I become mermaids instead? That way we can be-"

"I told you to forget that ever happened!" exclaimed Riko.

"Aw, you worry too much," replied Chika with a cheeky grin.

"Besides, the more you protest, the more Chika-chan brings it up," added You with amusement.

"I feel like I'm missing something," remarked Dia dryly.

"Actually, you did!" exclaimed the ginger as a light bulb went off in her head. "You forgot to mention the clam shells."

Dia blinked. "What clam shells?"

Chika smirked. "You know..." She exchanged a knowing glance with You, before the two of them leaned in towards the redhead and each grabbed one of Riko's breasts. "These clam shells," she clarified with a suggestive leer.

Two punches later and Chika and You were laid out on the floor with comical cranial eruptions atop their heads, courtesy of a very red faced Riko and her burning fist of fury.

"But...!" managed Chika, "You didn't mind last night...!"

One more punch was enough to KO the ginger.

"Pardon us," said Riko, voice laced with furious embarrassment. "I believe it's bedtime." The redhead shot a look at You, the diver picking herself up off the floor with a nervous chuckle.

"I guess Chika-chan's already asleep anyway," she said agreeably.

As You and Riko guided (read: manhandled) Chika out the door, Kanan and Mari exchanged a look. It was a look that Dia knew quite well.

"Alright, what have the two of you spontaneously decided on this time?" she asked.

"Have a seat, Dia," said Kanan as she invitingly patted the patch of floor next to her. "I think it's time for us to regale you with a tale of our own."

"Oh really?"

"Oh yes!" enthused Mari. "It's only fair that you get to star in your own story too, don't you think?"

"And what fable have you chosen to put me in?"

"Isn't it obvious?" asked Mari. "The only fable fit for our dearest Dia is none other than the story of Diamond White..."

Knowing what she knew of the original tale, Dia was skeptical, but ultimately accepting. "I suppose that's a respectable-"

"...and the Seven Deadly Sins!" finished Mari.

"...what."