I decided to try the Yukki because I was intrigued by the design that was similar to the Lunette, but it seemed to be made out of a material more similar to the LadyCup. It turned out, it's a little more "rubbery" or "plasticky" like maybe a Meluna or toy, rather than the smooth, frosted texture of the Lunette (haha maybe way too much detail there). If you look closely at the pictures, you'll notice it's actually made up of a bunch of small ridges (probably different than the LadyCup or Meluna). It has more friction when it comes to folding, and I feel that it stays in place better than the Lunette (never had ANY problems leaking on the whole period I tried it for).
I measured and you can see in the photos, I believe it is the same length as the Lunette (47mm). I took pictures both with (before I used it) and without the stem so you can see the difference.
It came in a really cute little tube, I don't know if you'll notice the proportions, but it was a LOT smaller than I thought it would be. About the size of my hands (and I have small hands). It did not come with any pouch.
Next to the Cup:
Some More Comparison with the Lunette and Keeper Cups (Both small sizes, btw)
The Yukki seems to have a narrower body than the Lunette, however it is a (slightly) stiffer material.
It's a little thicker and stiffer than the Lunette, but not too much. I like how it has enough friction and stiffness to stay put for me, but if you really want a smooth cup, I'd say go for the Lunette. The bottom ridges are a bit...for lack of a better word, sharper, so you may be able to feel it more than the Lunette.
You can see the squishiness/stiffness here:
Unlike the Lunette, its measuring marks are at 5 and 10 ml, rather than 5.5 and 13 ml, and it shows you the numbers, in case you forget (if you like to measure your flow, that is). Its name is printed on the inside, with a 1 for size 1 (small). The bottom is reinforced. The holes are at an angle, which I was nervous about, because I've never had a cup with angled holes before, but I didn't have any trouble cleaning it. The rim isn't thick like the keeper, but it is a little thicker than the Lunette. Personally, I would definitely recommend it to those waiting for Lunette to come available, unless you really want/need a smooth cup.
All in all I really like this cup. I had immediate success with it unlike all the other cups I tried (although it may just come from experience).
Oh! Almost forgot to mention - the stem was round and had the exact same "sharp" ridges that were on the bottom of the cup. I trimmed the stem (and the stem of my Lunette) because I have a low cervix (the cup sits literally an inch or less away from the opening). The Keeper's stem was just trimmed a bit because it was my first cup and I didn't use it enough to get used to it/trim the stem completely off.
As for the comparison with the Lunette, they're both about the same for me. I like the smoothness of the Lunette, but prefer the useful friction and stiffness of the Yukki (again, only slightly stiffer...it's still a squishy cup, but it just seems to stay in place better for me). Next period, I'll probably change them according to my mood.
Also, for those who are interested, I waited until FeminineWear stocked them to order from them. I live in the US, paid around $8 for shipping, and received the cup within 2 weeks. Much faster than I had expected.
If anyone has any questions, I'd be happy to answer them.
ETA: I just measured and the inside diameter is 30mm for those who are interested.