Shikaku[しかく] Silver925 / K18 Ring

What is universal beauty?

"What is the beauty that everyone thinks and feels beautiful?"

We have done a lot of design and have been thinking about it all the time.

Isn't the mathematically explainable "Surfaces" and "Lines" beauty just a universal beauty as we come touching with the world of origami and Bauhaus-like design?

Digital and hand work

In pursuit of mathematically explainable beauty, we needed the power of digital.

The shape of this ring is created by the orbit of a regular hexahedron (Cube) that keeps a certain angle.

The designer herself drew the prototype using CAD, a three-dimensional modeling software.

On the other hand, digital work alone does not make a ring that people can wear comfortably for a long time.

The level of completion depends on the work of human hands how to finish with good sensitivity.

Silver925(Sterling Silver) & K18 ring [Shikaku]. Geometric design ring with cubes circling around at a certain angle. It is a Japanese modern jewelry.

Enjoy the texture of metal

If you look closely at the side of the ring, you can find delicate lines in a radial pattern.

Actually, these come out pattern when it is produced with CAD data and output with a 3D printer.

Generally, this pattern is erased and polished.

Rather, we thought that this accidentally created pattern was "what an interesting expression!".

Silver925(Sterling Silver) & K18 ring [Shikaku]. Geometric design ring with cubes circling around at a certain angle. It is a Japanese modern jewelry.

Data traces on the side + light matte finish on the top

Of course, it is too rough to be a quality of jewelry.

At that time, Ayumi Maruyama, a craftsperson, has proposed to put a light matte finish on it after trial and error.

In addition, we decided to put another matte texture around the top of the ring.


The texture and the expression of metal are unique sensibilities and techniques that have been passed down to Japanese sword metalworkers.

In the MENTOSEN, each collection expresses the interesting texture of metal.

It is a new expression of metal that designers and craftsmen create by exchanging opinions.


It would be great to assemble the parts of gold

Only 5 square cubes are K18 gold.

"If you can assemble k18gold parts here, it would be cool ... but brazing would be quite difficult ...".

After making the platinum (or silver) and gold parts separately, it is a very difficult wotk to braze each one exactly.

Silver925(Sterling Silver) & K18 ring [Shikaku]. Geometric design ring with cubes circling around at a certain angle. It is a Japanese modern jewelry.

To be successful, the following conditions must be met.

(1) The output of the 3D printer must be accurately modeled.
(2) There should be no distortion at the casting stage, and the pattern on the side should not disappear.
(3) Finally, the craftsman should braze exactly and finish it properly.

Shikaku[しかく] Pt950/K18/Silver925 リング マリッジリング・日常使い MENTOSEN

"Let's do it! Because it's cool!"

Ayumi, craftsperson, said.

And finally the Shikaku[しかく] ring was completed.


Inside is also a cube

Rings are generally flat on the inside.

However, this ring dared to leave the shape of Cube on the inside.
We wanted to express the interest of modeling.

Of course, the most important thing is to have a comfortable ring that people can wear all the time in a daily life.

Ayumi finished with hand filing leaving each shape, and each corner is smoothed.

Even though edges and surfaces are left, it will not bother you at all when you wear it.

In this way, it was completed a smart and interesting ring.

Silver925(Sterling Silver) & K18 ring [Shikaku]. Geometric design ring with cubes circling around at a certain angle. It is a Japanese modern jewelry.

Reflection of light inside the ring

By leaving edges and surfaces inside the ring, when you look inside the ring, the light is reflected and moves.
A beautiful mirror finish that is easy to wear, while leaving a little inner edges and surfaces. It requires a highly careful handwork.

Hight level technique, careful work, sensitivity

Ayumi Maruyama was in charge of producing and finishing this Shikaku ring.
From a production efficiency standpoint, this ring must be a very inefficient piece of jewelry.
However, on the other hand, while she suffers from difficult productions, she seems to feel the joy of trying new things.
In the field of jewelery craftsmen which is dominated by male in Japan, she continues to work with reliable skills and new sensibilities.

People involved in the making

【About resizing】

It is basically not possible to resize keeping the shape of the cube. Resize and exchange within one month from delivery date will be provided free of charge. (Shipping fee and other costs incurred will be paid at customer's expense.)
If you need to resize in the future, please contact us as we can exchange the product at a special price or resize the cube so that the shape of the cube becomes longer or shorter.

【Engrave inside of your ring】Additional charged option 

We offer engraving on most of our engagement rings and wedding bands.
If you would like to engrave the internal characters, please click the purchase option and enter the desired characters according to the instructions below.

  • Possible characters: Uppercase alphabets, numbers, ".", "&", "To"
  • Number of characters:  Up to 15 characters . "."  "to" are counted as one character.
  • Characters example: 2030.11.11 A to B

Hand stamping 

Craftsperson stamp one by one by the hands.(Free for Pt950 / K18YG only)

This is a special service only for Shikaku. The Pt950 / K18YG ring will be engraved by craftsperson up to 15 characters free of charge.

リング 文字入れオプション 無料文字彫 MENTOSEN

We will make one by one according to your size

  • We will make one by one after receiving your order. 6 weeks to complete.
  • If you would like to ship within Japan, please specify the desired delivery date after 7 weeks from the order date. You cannot specify the date and time for overseas shipping.
  • If you make a mistake in your order, we will only accept cancellations and changes within 6 hours of your order.
  • Don't know the ring size
    If you are not sure about the size, please use the ring size chart or the size ring rental service.The size ring rental service is possible within Japan.

Sterling Silver925+K18ring /Pt950+K18 / Pt950+K18Click here

WEIGHT Japanes size #10 : Sterling Silver925+K18 約 2.5g/Pt950+K18 Appx. 4.5g 

Web shop acceptable size:Japanese size #6~18

Country of manufacture


  • Order mistakes can be canceled or changed only by email within 6 hours of ordering.
  • Please note that the Silver + K18 ring does not support free resizing. It will be resized for a fee.