Parisian “Smartlet One” Bracelet Launches on Makuake, Blending Beloved Watches with Smart Functions

Smartlet One: The Innovative Bracelet That Marries Your Favorite Watch with Smart Functions

LeaguE Co., Ltd. has commenced the project for “Smartlet One,” an innovative bracelet that enables the simultaneous use of a beloved wristwatch and a smartwatch or fitness tracker on a single wrist. The project launched on the crowdfunding service Makuake on September 10, 2026.

Smartlet’s initial pre-sale on Kickstarter, a global crowdfunding platform based in the United States, achieved over 500% funding, raising approximately 8,740,000 JPY. Furthermore, it was awarded a bronze medal at the “Concours Lépine 2025” in Paris, a prestigious invention competition with over 120 years of history, standing out among more than 250 inventions.

Its innovative concept and design have garnered significant recognition both domestically and internationally, with reviews featured in prominent overseas watch media and news outlets such as LE FIGARO, 20 Minutes, and WATCHPRO.

No More Choosing Between Your Favorite Watch and a Smartwatch

The proliferation of smartwatches has made it possible to access various functions from the wrist, including notification checks, health data recording, and cashless payments. However, many individuals cherish their mechanical watches and other beloved timepieces for their unique appeal, which smartwatches cannot replicate. This includes their design, craftsmanship, brand history, and sentimental value from long-term use or inheritance.

To address this dilemma, “Smartlet One” was conceived in Paris, France.

By employing a unique structure that places the wristwatch on the top side of the wrist and the smartwatch or fitness tracker on the underside, Smartlet One offers a new style that allows users to wear their favorite watch while simultaneously utilizing the convenient features of a smart device. This innovation frees users from the choice between a traditional watch and technology, enabling both design and functionality to coexist on one wrist.

Product Features

• 2-way structure allowing mechanical watches and smart devices to be worn on the same wrist.

• Broad compatibility with mechanical watches with lug widths of 18-24mm, supporting over 200 watch brands.

• Patented clip system enabling one-click, tool-free exchange.

• Constructed from surgical-grade 316L stainless steel, also used in medical devices.

• Lightweight design with a total weight of approximately 100g, and supports fine size adjustment using spare links.

Point 1: Elegant Integration of a Lifelong Watch and Smart Functions

Smartlet One allows your cherished wristwatch to remain on the top side of your wrist, while a smartwatch or fitness tracker is positioned on the underside. This means you can enjoy the original design of your watch while also leveraging the notification, health/activity logging, and payment functions of compatible smart devices.

Point 2: Universal Compatibility Across Watch Brands

Smartlet One is not designed for a specific watch brand. It features a universal design intended for combination with various watches and smart devices. Users can combine their favorite mechanical watch with their usual smartwatch or fitness tracker to suit their personal style.

Point 3: Instant Change in 1 Second with Patented Technology

Thanks to its unique patented structure, Smartlet One allows for quick, tool-free switching of watches to suit different occasions. Users can change their watch according to the time, place, and occasion (TPO) – a dress watch for business, a sports watch for holidays – while keeping the smart functions active.

Point 4: Parisian Aesthetic – Preserving Watch Beauty, Housing Smart Functions on the Underside

By placing the smart device on the underside of the wrist, the design ensures that the presence of the beloved wristwatch is not diminished when viewed from the front. Furthermore, high-quality stainless steel materials are used to naturally blend with the watch’s texture. Attention to detail in the finishing aims for the aesthetic of a bracelet worn with a watch, rather than just a functional gadget.

Point 5: Lightweight and Comfortable Design for Daily Use

The goal was not merely to enable wearing two devices, but to ensure natural, continuous use in daily life, whether at work, commuting, or going out. The total weight is kept to approximately 100g (excluding the weight of the mechanical watch and smart device), reducing the burden for everyday wear.

Product Overview

• Product Name: Smartlet

• Lineup: Classic / Shadow

• Material: Surgical-grade 316L stainless steel

• Surface Finish: Hand-finished hairline (Classic) / Matte black PVD coating (Shadow)

• Total Weight: Approximately 100g (excluding mechanical watch/smart device weight)

• Compatible Lug Width (Wristwatch): 18-24mm

• Compatible Lug Width (Smart Device): 20mm / 22mm

• Compatible Smart Devices: Apple Watch (all models except Ultra), Google Pixel Watch, Samsung Galaxy Watch, Garmin (some models), Fitbit Charge 5・6, Whoop 5・MG

• Standard Accessories: Dedicated buckle (for Classic or Shadow), spare links

• Optional: Additional watch connector (for Classic / Shadow)

Makuake Project Overview

• Project Name: [Achieve Both Looks and Functions!] A Bracelet that Allows Your Favorite Watch to Be Used Simultaneously with Notifications, Health Logs, and Payments

• Period: September 10, 2026 – October 30, 2026

• Sales Page: https://www.makuake.com/project/smartlet/

• Returns: Makuake-exclusive returns, including discounts of up to 37%.

About LeaguE Co., Ltd.

LeaguE Co., Ltd. is engaged in retail, wholesale, sales agency, and consulting businesses. The company actively focuses on crowdfunding, having led and supported over 100 projects for its clients.

• Company Name: LeaguE Co., Ltd.

• Representative: Shotaro Takechi, Representative Director

• Head Office: 2-9-10 Shibuya, Shibuya-ku, Tokyo 180-0004

• Established: April 2020

• Business: Retail/wholesale, sales agency, consulting

• URL: https://league-jp.com/