The Chibi Mermaid by ImoutoCommissions

Lettuce leaves her girls' night out with the other Mews with a plan in 
mind. She's spent the evening listening to Ichigo, Mint, and Zakuro talk 
about their experiences being made little with the Chibi Mew Mew pill, 
and at first, she simply felt left out because she's the only one who 
hasn't played with it, and the girls teased her plenty about that, but 
by the end, she found herself yearning to try it, and so, she leaves the 
night out with a plan.

Of course, by the time she goes to tell Pai about it, her confidence has 
waned, and she can just barely tell him about the other girls, and shyly 
admit, "I want to try something like that too, but...it's a little bit 
difficult, because I was stuck in a mermaid form the first time. I don't 
know how we would be able to, but if there were a way, I'd really want 
to."

Pai is receptive to the idea, simply responding, "I can take care of 
that part. In a few days, we can act out your fantasy without any 
difficulty."

And, true to his word, a few days later she comes home to find a salt 
water pool constructed and filled up for her. "This way," he says, 
"you'll be able to freely play as a mermaid."

"It's perfect," she says, "thank you!" With that, she strips down, 
climbs in the pool, and takes the little green pill, and in no time at 
all, it's taken effect. She finds herself growing smaller and smaller as 
her legs seem to fuse together, until they're replaced with a green 
tail. Pai offers her a small green bikini top, that fits her perfectly 
in her shrunken state, and now the fun can really begin for her.

Pai joins her in the water, with several games prepared for her to play. 
Really, it's more like she's doing tricks at an aquarium's water show, 
but Lettuce finds that she enjoys that quite a bit. She does flips out 
of the water, and then jumps through a hoop that Pai has prepared for 
her. He offers her small fish in return for her efforts, which she 
happily eats, briefly thinking of her cat friend as she does so, 
wondering if she enjoys them as well.

If he throws a fish and she makes a show of catching it, she will 
sometimes get another as a second treat, as if this were a trick as 
well. He even has a beach ball inflated for her to practice balancing on 
her nose, and though this doesn't go as well at first, she eventually 
starts to get the hang of it. It's fun and relaxing and so far removed 
from her daily life that she can see why all the other girls recommend 
it so much.

While she's playing with the ball, she fumbles with it, and she chases 
it across the pool, swimming after it until she suddenly stops and 
tenses. Pai watches this behavior, noting the relaxation that comes with 
a relieved look on her face, before she resumes chasing the ball, 
grabbing it to bring back to him.

"Did you just pee in the pool?" he asks her. Blushing furiously, Lettuce 
only nods, and he pats her on the head to reassure her. "It's perfectly 
fine," he says. "Actually, it's only natural."

Lettuce looks down then, noticing a bulge in his wetsuit, and suddenly 
grins, before diving under the water. She frees his member then, and can 
barely get her tiny lips around the tip, but does what she can, 
determined to get him off. So she wraps her small hands around his shaft 
to stroke him off while she licks his tip, and Pai gives a shudder of 
pleasure.

It takes her a bit more effort than it would at full size, but it still 
isn't long before her hands and her tongue are able to get Pai there, 
and when he suddenly comes, she struggles to swallow his load, only to 
fail, closing her mouth before he's done. When she surfaces, her face is 
covered in his semen, and Pai pats her head again.

"Is my little fishy feeling frisky?" he asks, and she pouts.

"A dolphin isn't a fish," she protests.

"Well, considering you're actually part porpoise," he replies, "I would 
say we're both wrong." Lettuce pouts, but he asks the question again, a 
little more directly. "Are you feeling amorous?"

Lettuce blushes, admitting, "Yes, I'm aroused, but...I know that I'm 
much, much smaller than I usually am. Even with my mouth I 
couldn't...fit you, so I don't think my size allows for penetration."

"You're more than likely correct," he says. "But that doesn't mean that 
I can't do anything for you." He holds out his arms, and she swims 
towards him, letting him hold her. With her tail curling around his 
midsection, he holds her close and finds the slit on the front of her 
tail, gently pressing his finger inside of her. As she is now, this is 
the biggest that she can take, and even with that in mind, he still has 
to be very gentle to avoid pushing her too hard.

Pai is slow and steady as he fingers her, and Lettuce sighs happily, 
giving into the pleasure. This is more than enough for her, and he's 
always been very skilled and precise with his fingers. He has her there 
very soon, as she tenses up again, before relaxing with a relieved 
expression and a moan, though it has nothing to do with her bladder this 
time. Now, she's relaxed in Pai's arms, and even the hold of her tail 
around his waist is very loose.

He chills the water a bit more, and though the temperature would be 
uncomfortable for an ordinary human, it's soothing for someone like 
Lettuce, and while he gently strokes her clit, she cuddles closer to 
him, until she slowly begins to drift off. They float in the water for 
some time, and he does not get out until after the effects of the pill 
wear off, returning her legs to normal so that he can carry her to bed.