This is one of the yurified fairy tales ("Yurimm Fairy Tales") from Yuri Shimai/Hime magazine. I've translated it in full rather than writing up notes on it.
For scanlations of manga (and other Yurimm Fairy Tales) from Yuri Shimai/Hime, see Lililicious. Lililicious is also planning to scanlate this story.
They were really yuri... maybe?!
It's true!
Yurimm Fairy Tales
Chapter 3 "The Red Demon Who Cried 'Moe!'[note: Loosely, a term used to describe a cute character. Can also be used to denote a person who likes such characters.]'"
That time when I put the tea on and await her arrival...
Story: Ruri Hozuki
Art: Sakura Shio
An innocent Red Demon-chan left Demon Island and settled in the countryside. Her dream was to become the girlfriend of a human girl. She racked her brains for ideas, and came up with a modest plan: to put up a notice.
---I've made some tasty sweets and tea. Come on over and see me! [heart]
The Red Demon---
The Red Demon-chan already had a particular girl from the village in mind.
"I don't know if that's a good idea..." The Blue Demon-nee-san [note: In this case, used to refer to an older girl.] gave a wry smile around her mouthful of sweets. Though she looked cool on the outside, the truth was that she was utterly smitten with the Red Demon-chan, and had followed her here from Demon Island.
The Red-Demon-chan was completely oblivious to the other demon's feelings. She cheerfully readied tea and sweets for another day of waiting, continuing to indulge in her fanciful notions.
"Hey, look at this sign!"
"It says to come for tea."
"But it's from a demon, isn't it? I'm scared!"
Oh, dear! The Red Demon-chan was terribly shocked by the village girls' words.
"It was inevitable, Red Demon-chan. But I have a better idea." The Blue Demon-nee-san decided to lend her a hand.
-gah-
"Listen to this..."
"Whaaat?! You think I should do something that extreme...?"
The Blue Demon-nee-san's plan was that she would attempt to kidnap the girl from the village and the Red Demon-chan would swoop in and fight her off.
"But I could never hit you, Blue Demon-nee-san. And that plan would make you the bad guy..."
"Well, if I do this, maybe that will change your mind?"
The Blue Demon-nee-san suddenly ripped her clothing off and attacked the Red Demon-chan, who was sitting in the bathtub.
"I've been wanting to do this for a long time, Red Demon-chan. Maybe I should devour that village girl you hold so dear, too?"
"Wh-wh-what did you just say?"
Oh, dear. The Red Demon couldn't help but be provoked; she rose from the tub, stark naked. The Blue Demon-nee-san's smile widened.
"Don't you dare! I'll do it. I'm going to do it!"
The Blue Demon-nee-san felt a tiny stab of loneliness at the Red Demon-chan's newfound determination.
If you're that innocent, I'll eat you all up!
-splash-
Don't touch her!
-booom-
Red Demon: How dare you?!
"My, aren't you cute. Want to be my girl?" The Blue Demon-nee-san suddenly descended upon the village girls, who were playing peacefully. Her target was the object of the Red Demon-chan's affections, of course. Her performance was so passionate, it was difficult to believe that it was all an act.
"My, you're blushing. You aren't averse to this at all, are you?"
Just as one pair of lips was about to brush the other, the Red Demon-chan hit the Blue Demon-nee-san with a megaton punch. "Nooo! Stoop! Don't do iiit!"
It was a direct hit to the face! The Blue Demon-nee-san was KO'd.
The Red Demon-chan was confused. She didn't know which had bothered her more: the kidnapping of the village girl or the Blue Demon-nee-san's flirtation with her...... Such an enigma a maiden's heart is. An enigma indeed.
Getting to be friends with her is like a dream come true.
"Thank you! I see now I had the wrong impression of you."
"Let us be friends!"
The Red Demon-chan was surrounded by girls. In the space of a few moments, her popularity had shot through the roof. She was getting even closer to the girl she admired than she'd dared to expect. It was like a dream come true.
When she returned home at dusk, she found a letter awaiting her.
---Red Demon-chan,
I'm glad you were able to make friends with that girl. I hope the two of you become even closer. You're shy, so you'd better try and make the first move once in a while. I've decided to go on a trip. I don't think we should spend time together anymore, since it might give those girls the wrong impression.
Love,
The Blue Demon---
What a disaster! The Red Demon-chan rushed to try and catch the Blue Demon-nee-san.
The Blue Demon-nee-san was always so kind to her. Always. And this time, she'd sacrificed herself to make the Red Demon-chan's dream a reality.
"I've been so terrible, only thinking of myself all this time. How self-centered!"
The Red Demon-chan ran, and ran, and ran some more, until finally, she spotted the Blue Demon-nee-san in the moonlight. How small and frail her back looked! The Red Demon-chan had never seen her like this before.
"Blue Demon-nee-san, wait!"
Shocked, the Blue Demon-nee-san turned to see who had called her. It was the Red Demon-chan, who stood there with flushed cheeks, panting for breath.
"What's wrong, Red Demon-chan?"
Rather than answering her, the Red Demon-chan flung herself at the Blue Demon-nee-san's chest. Her uncontrollable tears coursed down her cheeks and dampened the Blue Demon-nee-san's coat.
"Don't go, Blue Demon-nee-san! I can't live without you!"
The Blue Demon-nee-san embraced the Red Demon-chan fiercely. She was truly happy, from the bottom of her heart.
She murmured, "The truth is, I can't either, Red Demon-chan."
The moon's radiance increased as it continued to bathe the pair in its light.
She finally realized who it was she truly loved.