Here is the masturbator Gokusai Uterus Duo, a product that seems to be well appreciated by customers on my partner Motsutoys. A short while ago, I reviewed the R-18 Onahole, a model designed to improve your penis endurance through the Mushroom Forest Girl training. But this time, we’re off to a new world.

Lately, I’ve been reviewing several Japanese masturbators, like the Ondo! Nupu, the Real Body 3D Maria Nordal and more less recently, the Puni Virgin 1000 Fuwatoro. Here, it’s a special kind of masturbator, with a fake hymen inside, a rather weird concept, but again, it’s a Japanese masturbator, you have to expect everything! So here is my review of the masturbator Gokusai Uterus Duo from Magic Eyes!

Gokusai Uterus Duo packaging

The front side of the Gokusai Uterus Duo box

The front of the box

Once again, with Japanese packaging, there is a lot to say! Who said that packaging wasn’t interesting to explain to you? Here we have a very detailed box, which reminds me a little bit of the box of the masturbator The Mouth of Truth Perorin, especially in terms of its opening and its shape, which looks a bit like a jewelry box. On the front side, we discover two elongated girls in the shape of an S or 69 who look at each other in little black outfits.

Details of the box

The side of the box with the opening

The side of the box with the opening

On this side, we discover the mention “The dream of a butterfly from Chuang-tsu” as well as the logo of the manufacturer, Magic Eyes. It is also mentioned that it is a texture called “UnRealSkin” that we will see later. On the slice, we can see the sleeve in a drawing, with an internal cut-out and explanations on the two directions of use of this one. Then, right next to it, the dimensions and weight of the masturbator.

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The detail of the inner sleeve is indicated on the box.

Behind the box is the masturbator in close-up with internal details of the sleeve and the explanation about the hymen present in it. In any case, some kind of hymen. For the opening, it’s like a jewelry box, with inside, simply the masturbator wrapped in a plastic pouch. Here, we don’t have a free lubricant sample.

The story of the masturbator

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The story, written in Japanese of course!

The last thing to explain is the little story on one of the slices of the box. It tells us that we’ve always been close to two pretty girls from the neighborhood. It seems that we are secretly in love with both of them at the same time, the elder Yume, who is more aggressive than the younger Nemu, who is pure and faithful. However, we never proposed anything to the girls because our friendship was important and we didn’t want to jeopardize it.

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And here’s the masturbator we’re discovering

But one day an angel appears in front of Yume, who promises her that she will find love with the person she chooses. However, the next night, the moon turns red. Nemu, her youngest daughter, summoned a demon and signed a contract with him. By exchanging her soul, she can become one with the person she loves. So we find ourselves between an angel and a demon, who will draw us into a particularly complicated trio. Only the Japanese tell us stories like that.

Gokusai Uterus Duo physical details

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Once out of the box, we find the masturbator in a pocket…

Quite honestly, it’s not exactly a visually pleasing masturbator. I don’t know why, but it makes me think of a piece of meat or something. I think it comes from having this very red part in the middle that I don’t really like visually.

One of the masturbator's entrances

One of the masturbator’s entrances

Otherwise, as you can see on the pictures, it is a masturbator with a double entrance and with two distinct designs. As you must have understood, we find Yume’s vulva and Nemu’s vulva. So it’s two orifices, one of which is tight and the other is virgin! This is one of the important points of the concept of this masturbator. On the realistic side, it’s correct, let’s say that the two orifices are not too badly made. On one of the ends, there is even a small hole (but not penetrable) that corresponds to the anus of one of the two sisters.

Size of the masturbator

A compact masturbator

A compact masturbator

No doubt, we’re on a pocket masturbator! This one is compact, not very wide, it almost fits in one hand. Indeed, this one measures 15 cm (5.90′) of total length, for an insertion length of the same dimension. And on its width, it is 7.8 cm (3.07′). The holes are very small, but the material allows you to stretch them to get your penis inside. Mine fits without any problem.

The other details

The opening is not very big

The opening is not very big

What I have to tell you about this masturbator is its weight! It weighs 430 grams, which is almost half the weight of a Fleshlight masturbator for example. Otherwise, I think I’ve got it all figured out.

Gokusai Uterus Duo materials

The tunnel of the Japanese masturbator in detail

A texture consisting of 4 materials

Attention, this Gokusai Uterus Duo masturbator uses 4 different materials. It doesn’t look like that and yet it is. As I indicated on the box, it’s a material called “UnReal Skin”. It is still TPE/TPR, but more worked and with very distinct textures. The goal is to create a more realistic masturbator than the average.

The four materials of the masturbator

You can easily bend the sleeve

The central part folds easily

You have an external part, which gives a skin effect, which is already found on many Japanese TPE/TPR masturbators. Then you have a more elastic material on the inside, a layer of vaginal mucosa and a harder material, which is supposed to reproduce the uterine area.

Sleeve construction

The other orifice of the masturbator, tighter

The other orifice of the masturbator, tighter

You got it right, on this masturbator, you have two entrances. Well, let’s say one entrance and one exit that can be used both ways. Yeah, it’s not simple. You have a first entrance, Yume’s side, which offers a sleeve that starts with rows of small ridges that give a certain impression of narrowing of the vagina with, at the end, the part that reproduces the hymen, which is harder than the rest of the materials present and which rubs on the glans of the penis.

The Gokusai Uterus Duo sleeve in my hand

The Gokusai Uterus Duo sleeve in my hand

Then you have Nemu’s side, which starts on bumps, with a uterus that extends up to 8 cm (3.14′), smaller than her sister Yume. Because yes, there is a difference in the tunnel between the two sides, because they are made differently. It’s as if there was a kind of double tunnel inside where the penis passes through a slightly different place. On the other hand, the external texture is much greasier than the R-18 that I reviewed a little while ago. When you clean it, it’s less greasy, but I must say it’s not as soft on the outside as this one.

Gokusai Uterus Duo use

The Gokusai Uterus Duo next to the R-18

The Gokusai Uterus Duo next to the R-18

How to use a masturbator, the answer is obvious! You need a penis, it is preferable, otherwise it will be less fun! But the concept of this masturbator is that there is a fake hymen inside and therefore you can only enjoy Nemu’s virginity once. So be careful, if you want to enjoy it, you will have to use this masturbator on the Nemu side for your first use. But that’s not all there is more to know, so let’s take a little about it!

How do I use this masturbator?

Comparison next to the Ondo! Nupu

Comparison next to the Ondo! Nupu

You know, a masturbator is like a dildo, it’s the easiest type of sextoy to use. A little bit of lubricant in the sleeve or on your glans, you grab it with one hand and you start to go back and forth on your penis! But you can also, depending on its size, use it with the Handy masturbator, to synchronize it with a porn video. But it is also possible to use it with your partner, who will be able to move it for you.

What lubricant to use with?

Who can answer me? If you read our reviews regularly, you know very well what I’m going to tell you. With a masturbator such as this one, you must use water-based lubricant. Since you don’t have a lubricant sample available, you will have to choose a lubricant. You take the one you want, as long as it is water-based. At the moment, I’m still using Sliquid Satin, Buck Angels, Sliquid Organics Sensation but also Motsutoys Tyo and UnisX vaginal lubricant.

How’s the cleaning going?

Comparison with the masturbator The Mouth of Truth Perorin

Comparison with the masturbator The Mouth of Truth Perorin

As usual, with a masturbator of this kind and which has in addition, two orifices, it is nevertheless relatively easy. It is necessary to use warm water and a little soap. This is the basis, because the goal is to remove the rest of lubricant and secretions. For my part, I also use a small stick to clean more easily the inside and a small cleaning on the outside with a toy cleaner like Sliquid Shine. Then let it air dry and you’re done with that step.

Gokusai Uterus Duo efficiency

The Uterus Duo next to the Puni Virgin 1000

The Uterus Duo next to the Puni Virgin 1000

Honestly, I’m not sure how to tell you what I think of this masturbator. First of all, the concept is really peculiar and I have to say that I don’t completely agree with it. Reproducing a fake hymen in a masturbator is quite strange and even almost disturbing. It’s really a Japanese concept, but I’ll tell you what I think of this Gokusai Uterus Duo!

Getting started

Concerning the use of this masturbator, it is a soft sleeve without hard parts. In short, you will have it in your hand, but without any real grip! For my part, I don’t find this to be a defect, but some people prefer with a shell for the grip. Whether it’s the inside or the outside, the texture is the same. I find that it’s rather practical, because you can put pressure on the masturbator to make the penetration even tighter, but it’s a matter of taste. Anyway, despite this element, you can hold it well without it slipping!

Two different tunnels

It’s pretty peculiar, but there are two different tunnels in this masturbator. You have one tunnel longer than the other, that’s also the concept, because one is virgin and the other is not. It’s the hymen that does it all at this level. Because yes, on one side there is a thin layer that represents that hymen. The two entrances are quite tight, maybe a little too tight for some people. On the side of Yume’s tunnel, this one is more open at the beginning with a light stimulation and a rather realistic feeling, even if you don’t feel the same as a real vagina.

On the other side, it’s the part with Nemu and her hymen. Here, the tunnel is narrower at the beginning, then the further the penis goes, the more you feel a thin part blocking the penis. It is the hymen that you have to penetrate. You really have to be careful here. Indeed, as I indicated, there are two tunnels and when you don’t pay attention, you can end up with only one tunnel or almost one. Because in this direction the glans of the penis will often enter in conflict with this layer of material and will almost come out on the other side of the masturbator. Sometimes the glans will get stuck, sometimes the glans will pass through. It’s quite strange.

A rather strange masturbator

Yeah, that’s really what I’m getting out of this masturbator. Its construction is really not common and I can tell you that it is different from the other masturbators I had the opportunity to review on the site. There is a softer, more classic side with a light stimulation and on the other side we have a tunnel with harder materials and a more intense stimulation.

And I have to admit, it’s a little disturbing. Because it highlights the tunnel of the virgin, which I don’t necessarily like in the message that the masturbator can deliver. As far as I’m concerned, the hymen is pierced but still acts as a blockage of the glans and stimulates the glans and the crown of the penis quite effectively.

I think it’s a masturbator that will be to the liking of some people, but I must say that I haven’t really accepted the concept. It’s a bit too weird for me, even if I have to say that it’s a rather successful masturbator with its 4 different materials that make it quite different from a masturbator with a unique texture.

Gokusai Uterus Duo final thoughts

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A strange masturbator, a weird concept, but a good masturbator overall.

Weird and freaky is what I’m getting out of this masturbator. It’s only my opinion, because I can’t say that this masturbator isn’t good, on the contrary. But I didn’t really get hooked on the concept of the hymen and the virgin. Still, I find it a bit disturbing in its concept. I know it’s necessary for everyone, that’s what I’m saying. It will find its audience and there’s nothing wrong with that. But I’m not part of it.

It is better not to have a penis that is too wide, as you will feel much less sensation from the texturization of the tunnels. Maybe that’s also why I didn’t completely hang on to it. You will enjoy it more with a penis of 3 cm (1.18′) in diameter for example. In any case, for its price, it is affordable and offers something different than a more classic masturbator! If that’s your thing and you’re looking for a masturbator of this type, this is your chance to try it!


  • Two holes
  • 4 different materials
  • A fake hymen for those who like
  • Japanese style packaging
  • Compact and transportable


  • No lubricant sample
  • A somewhat disturbing concept
  • Not very suitable for penises larger than 3 to 3.5 cm (1.18′ to 1.37′)
Review Date
Reviewed Item
Gokusai Uterus Duo
Author Rating
Product Name
Gokusai Uterus Duo
EUR 29.95