This is a wearable review of the new Oceanus Manta OCW-S40-5AJF, released in April 2025. This small-diameter model joins the Oceanus Manta line, which strives for slimness and elegance. When I first learned of this model, I was surprised by its price and wondered what position it would take in the women's watch market. However, by the end of the review, I realized that this model is not only suitable as a daily watch for women, but also represents a model that symbolizes the expansion of the luxury women's watch market.
Photographs & Text by Chieko Tsuruoka (Chronos-Japan)
[Article published on January 9, 2025]
What kind of model is the Oceanus Manta OCW-S40-5AJF?
The year 2025 marks the 20th anniversary of the birth of the Oceanus. One of the models created to celebrate this milestone is the Manta OCW-S40-5AJF, which we will be wearing and reviewing today.
Tough Solar. Approximately 17 months on a full charge (power saving mode). Ti case (29.7mm diameter, 8.7mm thick). 10 bar water resistance. 165,000 yen (tax included).
The Oceanus line has expanded its lineup over its 20-year history, with the Manta being launched in June 2007. The first model was the world's thinnest chronograph, the OCW-500, and since then, the series has pursued slimness and elegance. Not only is it thin, but it also boasts an intricate design and a color palette that sets it apart from conventional solar watches, giving it a luxurious exterior that stands out even among the Oceanus line.
This model is based on the three-hand model "OCW-S400" from the Manta series and is a slimmer, smaller-diameter model for women. Other notable features include a pale beige vapor-deposited bezel and dial, a first for the Oceanus, and a sapphire crystal ring on the bezel, a first for an Oceanus women's model.
In addition, this model also comes in different colors, including the first light blue Oceanus model, the Manta OCW-S40-2AJF, and the 41.3mm diameter Manta OCW-S4000SG.
Since Oceanus is being promoted as a "pair watch," it would be fun to buy matching watches for partners.
As Oceanus celebrates its 20th anniversary and continues to expand its appeal, let's take a look at the capabilities of its latest model.
Is the selling price of 165,000 yen including tax high?
This watch features a pale beige dial that has been coated with a vapor deposition process. The color is eye-catching, and unusual for both the Oceanus, whose signature color is blue, and for a watch, but what is most surprising is the texture.
Because it's solar-powered, like other solar watches, the dial isn't made of brass or other metals, but of polycarbonate, which allows light to pass through. While some Oceanus models, powered by Casio's proprietary Tough Solar solar power generation system, generate enough energy to run the watch by receiving light only from the inset dial, this model's simple three-hand display means that light is transmitted throughout the entire dial (though many inset-dial solar models also use polycarbonate for the rest of the dial). However, the dial, with its textured edges and the lines of light that appear when you change the angle of the watch head, has a texture that almost resembles brass. Incidentally, my colleague, Yuto Hosoda, shared his impressions of different sizes of this model, and even he was amazed by the quality of the dial.
The sapphire crystal bezel ring is also given a pale beige color by vapor deposition. The sapphire crystal bezel, with its different luster from ceramic, not only enhances the aesthetic appeal, but is also scratch and discoloration resistant, which is a plus. I've had many experiences where I accidentally bumped my watch into something and scratched the bezel (even though the bezel is designed to protect the watch from such impacts), so while it might be one thing if it were a tool watch, it's reassuring to know that, with a business watch like this, you can prevent unsightly scratches in advance.
To be honest, I thought the price of 165,000 yen (including tax) for a ladies' solar radio-controlled watch with basic three-hand functionality was quite high. Looking at competitors in the same genre, most models are priced around 100,000 yen. Therefore, when I first heard about this model, I had the impression that it was expensive, but when I actually got my hands on it and used it, I realized that it was a luxury watch worth the price.
Not only is the dial's texture excellent, but the sapphire crystal bezel sparkles and exudes presence on the wrist, resulting in a very satisfying experience. Incidentally, sapphire crystal is hard and difficult to process, so it's not commonly used for anything other than crystals, being limited to a select few luxury watches. Oceanus watches, such as this one and the "OCW-S7000," use sapphire crystal for the bezel, sometimes achieving a variety of colors through vapor deposition or even complex shapes, yet still keeping the price in the 10 to 20 yen range, can be said to offer excellent value for money. Incidentally, the sapphire crystal is supplied by a domestic manufacturer, and the manufacturer and the Oceanus brand have collaborated to create a stunning bezel at this price range.
The titanium case and bracelet also add to the satisfaction with the price. The lightweight and thin case and bracelet make it very comfortable to wear. I've reviewed the Oceanus several times, and each time I was impressed by how comfortable it was to wear. The thin yet complex shape and the use of both satin and polished finishes give the watch a luxurious feel, not just on the dial but throughout its entire exterior.
Furthermore, the buckle has a fine adjustment function that allows you to shorten or lengthen the bracelet's inner diameter by 3.8mm without tools. This function is very convenient, and the thickness is not significantly different from previous models without this function (although I haven't actually measured it), which once again demonstrates the greatness of the Oceanus development team and this watch.
Looking at the actual watch, the price of 165,000 yen (including tax) is not particularly high, and in fact it offers good value for money, but as competitors shift from domestically produced solar radio-controlled watches to quartz and mechanical watches, including those from overseas brands, it seems that positioning it in the market will be difficult.However, the fact that a solar radio-controlled watch is now available at this price suggests that the market for luxury ladies' watches is expanding, and this watch will meet the increasingly diverse needs of its users.
The convenience of solar-powered radio-controlled watches makes them ideal for working women
When reviewing the Oceanus, we tend to focus on the quality of the exterior and the excellent fit, but its outstanding functionality is also one of its strengths.
Because the Oceanus is a radio-controlled watch, it always displays the correct time as long as it receives standard radio waves. Even with quartz watches, you don't need to manually adjust the time that often, but the function that automatically adjusts the time by receiving radio waves once a day was surprisingly convenient and helped me out in my busy daily life. Incidentally, to manually receive standard radio waves, press and hold the push button at the 4 o'clock position on the case.
This model does not have the Mobile Link function, which I personally find very useful on the Oceanus and G-SHOCK. The Mobile Link function links the watch to your smartphone via Bluetooth, allowing you to configure various settings on your smartphone. Since there are few opportunities to operate this model in Japan, the need for Mobile Link is probably low.
Positioned as a luxury solar radio-controlled watch for women
We reviewed the Manta OCW-S40-5AJF, which was released this year to mark the 20th anniversary of the birth of Oceanus.
I've worn and reviewed the Oceanus several times, but this is my first time with a ladies' model. Even though it's smaller, the Oceanus's merits, such as its well-crafted exterior and ease of use, remain intact, while the watch also has an elegance that subtly adds a touch of elegance to a woman's wrist. Its high price of 165,000 yen (tax included) for a ladies' solar radio-controlled watch is well worth it.
As mentioned in the article, I wondered whether Casio's positioning in the women's watch market might be more difficult than that of its main competitors, Japanese watch brands like Oceanus and G-SHOCK. However, solar radio-controlled watches, once considered more casual than mechanical watches, have recently seen a wide variety of high-end models. As the market for female watch users has expanded, the women's model genre has become more diverse. Considering Oceanus as one of the first to offer "luxury solar radio-controlled watches for women," this watch can be considered a pioneer and a symbol of the expansion of the women's watch market. I hope to see further expansion of this genre, starting with the OCW-S40.
