Japanese wearable startup Soxai has officially introduced the Soxai Ring 2 in Japan, aiming squarely at people who want serious sleep tracking and health insights in a tiny, lightweight form factor. With a slimmer body, upgraded sensing hardware, and a subscription-free model, the new ring is positioned as a practical alternative in the fast-growing smart ring market.
A big part of the update is Soxai’s redesigned optical heart sensor. The company calls it the “Deep Sensing” PPG sensor and says it was developed in-house, combining optical design with its own algorithms to improve accuracy. In everyday use, this sensor is designed to track key wellness metrics such as heart rate, blood oxygen saturation (SpO2), and sleep stages. Soxai also notes that the system can surface indicators linked to sleep apnea risk, focusing the Ring 2’s feature set on long-term sleep awareness rather than flashy smartwatch-style extras.
Beyond the optical sensor, the Soxai Ring 2 includes an AI-assisted 3D accelerometer to help interpret movement and nightly patterns, plus a skin temperature sensor that can add context to recovery and sleep-related trends. Together, these sensors feed into the ring’s companion smartphone app, where users can view sleep scores, total sleep duration, and night-by-night sleep patterns, along with broader lifestyle insights.
Soxai also emphasizes coaching and habit support. The companion app offers sleep-improvement tips based on algorithms supervised by experts associated with the Japanese Society of Sleep Research. It’s worth noting that blood pressure measurement is not included, so anyone shopping specifically for that feature will need to look elsewhere.
In terms of comfort and wearability, the Soxai Ring 2 has been slimmed down compared to the previous generation. It measures 6.7 mm wide and 2.7 mm thick, with a weight between 2.1 g and 2.7 g depending on size. The outer shell is made from a titanium alloy for durability, while the inside uses synthetic resin. Buyers can choose from five finishes: silver, matte silver, matte black, pink gold, and gold.
Battery life is another headline feature. Soxai rates the Ring 2 for up to 14 days on a single charge, varying by ring size and how it’s used. Charging is handled via contactless NFC wireless charging, with a full charge taking roughly 60 to 120 minutes. The ring supports Bluetooth Low Energy 5.0 and has a 100 m water resistance rating, making it suitable for daily wear, workouts, and swimming.
Pricing in Japan is set at ¥39,980 (around $257), and Soxai is highlighting that there’s no subscription fee required to access the core experience. The Soxai Ring 2 is already on sale through Soxai’s online store and major Japanese retailers, with the option to order a sizing kit or purchase directly if you already know your ring size. As of now, Soxai explicitly states the Ring 2 does not ship outside Japan.
