Casio Oceanus S400 Series 40mm Titanium OCW-S400 (OCW-S400). Current Prices, JDM Listings, Market Analysis

The Casio Oceanus S400 Series is a solar-powered, multi-band titanium dress watch from Casio's premium Oceanus line, sold primarily through the Japanese domestic market. Because it sees limited gray-market distribution in the US, OCW-S400 price data requires active sourcing from Japan rather than domestic retail channels. Tonbo tracks this model because the gap between JP acquisition cost and US resale value has consistently produced verifiable margin, with 18 confirmed eBay comps anchoring the current range. At a US median of $900, this is a mid-four-figure JDM opportunity worth understanding before you buy.

Current US Market Value

Based on 18 verified eBay sales, the Casio Oceanus S400 Series 40mm Titanium OCW-S400 currently trades at a US median of $900. The interquartile range runs from $812 at the 25th percentile to $963 at the 75th percentile, which is a reasonably tight spread given the sample size. Comp quality is rated 🟢 Verified comps, meaning the underlying sales data has been reviewed for condition and relevance rather than pulled raw. Eighteen comps is a workable dataset for a JDM-only model, though it does mean individual outliers can move the median more than they would on a deeper-comped reference. Treat the $812 floor as a conservative planning figure and the $963 ceiling as achievable on a clean, well-presented example.

Active JDM Listings

As of mid-June, the OCW-S400 for sale in Japan is appearing across Yahoo Shopping at prices that cluster firmly around the ¥154,000 mark, with a couple of outliers sitting lower. At current exchange rates, that upper cluster converts to roughly $1,000 USD before shipping and import costs, which still leaves room depending on where you land the unit. Here is what the active window looks like right now:

• Four concurrent Yahoo Shopping listings at ¥154,000 (June 11)
• One Yahoo Shopping listing at ¥127,980 (June 11)
• One Yahoo Shopping listing at ¥119,900 (June 11)

The tight clustering at ¥154,000 across four separate sellers suggests that figure represents the current floor for new or near-new Japanese retail stock. The two lower listings are worth investigating for condition notes before acting.

Recent Alert History

This model has been generating consistent signal over the past 90 days, with four alerts fired across three different tiers. The most recent was an opportunity-tier alert on June 8, where a landed cost of $720 against a US median of $900 produced a 20% gross margin. Earlier in the window, a strict-tier alert on May 28 showed the strongest margin at 28%, with a landed figure of $561 against a then-median of $775. Two alerts on May 31 both cleared the opportunity threshold as well, landing between $667 and $695 against an $875 median. That pattern across multiple tiers and dates indicates this is an actively moving model rather than one that fires a single signal and goes quiet. You can review current and historical signal data for this reference on the Tonbo signals page.

Japan vs. US Price Gap

The OCW-S400 price differential between Japan and the US exists primarily because the Oceanus line is positioned as a flagship domestic product in Japan, sold through Casio's own retail network and authorized dealers rather than international distributors. US buyers who want one have to go through gray-market importers or source directly from Japan, which adds friction and suppresses supply. That supply constraint is what keeps the US median elevated relative to Japan street prices, and it is what creates the margin window you see in the alert history above.

The main risk factor here is condition variance on used Japanese listings. Without physical inspection, it is difficult to verify whether a unit described as mint or near-mint actually presents that way on arrival, and condition has a meaningful effect on where a sale lands within the $812 to $963 range. That is a standard JDM sourcing risk, not specific to this model, but worth building into your margin math before you commit. Current deals being tracked can be found on the Tonbo deals page.

Track Casio Oceanus S400 Series 40mm Titanium OCW-S400 on Tonbo

If you are following the OCW-S400 or looking to buy OCW-S400 from Japan at the right moment, Tonbo surfaces the signals before the window closes. The Collector tier is free to start at tonbomarket.com/dashboard and includes a five-model watchlist with no credit card required. If you want real-time Discord alerts pushed to you when a strict or opportunity-tier signal fires on this reference, the Member tier is $10 per month. No upsell, no lock-in. The model does the work. Tonbo just tells you when to look.