MENTOSEN Diamond & Bridal Fair: May 22 (Fri) – June 9 (Tue)
We are excited to announce the Diamond & Bridal Fair at our MENTOSEN flagship studio from May 22nd (Fri) to June 9th (Tue), 2026.
We will be showcasing a unique selection of fancy-cut diamonds, as well as brown, yellow, and other colored diamonds—pieces we truly felt would be wonderful options for you.
With the special support of our long-trusted diamond dealer in India, these rare and distinctive diamonds will be on display in-store.
In addition to the MENTOSEN Ring Collection, we will also be offering personalized consultations for fully custom-made jewelry.
Customers who place an order during the fair will receive a special gift. 
Special Gift
Place an order during the event to get a free MENTOSEN original origami craft kit!
Few beautiful designs are available for you to choose from.
How to Order
（MENTOSEN Original Rings）
Set rings designed to stack beautifully along curved surfaces, and technical stone-setting.
1. Consultation
We provide personalized consultations at the MENTOSEN Studio. (SHINKO STUDIO Shop)
Book Your Appointment Here
Diamods & Weeding Rings Consultation
To help us assist you smoothly, please share any preferences you have regarding budget, carat size, or other details when booking.
2. Order & Payment
Crafting your piece begins once payment is completed.
3. Crafting Your Ring
For the MENTOSEN Ring Collection, unless the item is currently in stock, each piece is carefully crafted and takes approximately 1.5 to 2 months from order to completion.
Delivery timelines for custom orders selected from loose stones will vary.
Please refer to the Custom Order section below.
You can choose to collect your finished piece at our studio or have it delivered to your address.
Custom-Made Rings
During the fair, we offer a special selection of loose color and fancy-cut diamonds. This is a fully bespoke experience, personalizing everything from stone selection to final design.
- Fancy Color Diamonds: Diamonds in shades other than colorless (white), such as yellow, brown, and pink.
- Fancy Cut Diamonds: Diamonds in various unique shapes other than the standard round brilliant cut, including marquise, pear, and emerald cuts.
ou will consult directly with a MENTOSEN designer, who will propose an original design tailored perfectly to your chosen loose stone.
To help you visualize the final piece, the design can be reviewed using a 3D-printed model.
1. Selecting Loose Stones & Design Consultation
We provide personalized consultations at the MENTOSEN Studio. (SHINKO STUDIO Shop)
Book Your Appointment Here
Diamods & Weeding Rings Consultation
Each fancy color and fancy-shaped loose stone has its own unique color and shape. Please note that quantities are limited.
2. Design Proposal & Quotation
Your design will be presented using a full-scale, 3D-printed model.By trying on this actual-size model, you can easily visualize the ring’s overall volume, balance, and comfortable fit on your finger.Please note: It takes approximately 3 weeks to 1 month to prepare your design proposal.
3.Order & Payment
Crafting your piece begins once payment is completed.
4. Crafting Your Ring
It takes approximately 2 to 2.5 months from the official order for your piece to be completed, as each item is carefully crafted
If you have a specific deadline or are in a hurry, please feel free to consult with us.
5. Intermediate Size Check
For platinum or gold rings, you can check and verify the ring size during the production process before the final completion.(Please note: Depending on the design, an intermediate check may not be required.)
Service
1. Inside Engraving
Complimentary Engraving (Free):
Engraving inside the ring is available free of charge. Up to 18 characters can be engraved using the standard font below.
(Note: Upper-case letters only. Numbers and alphabets are limited to capital letters.)
Laser Engraving (Paid Option):
¥3,300 (including tax) | Up to 18 characters available using the font options below.
2. Resizing
Available in Japanese ring sizes, with 0.5 size increments.
Within the first month, we offer one complimentary resizing within ±2 sizes from your original ordered size.
Works Our Custom-Made Rings
