Citizen Tsuyosa Strap Size: Compatibility Guide

You’ve just unboxed a Citizen Tsuyosa, or maybe you’ve been wearing yours for a few weeks, and you’re already thinking about swapping the bracelet for something with a bit more personality. Maybe you want a vintage leather strap for the office, or a bright NATO for the weekend. But before you start shopping, there’s one number you need to know cold: the lug width. Getting this wrong means ordering a strap that simply won’t fit, and that’s a waste of time and money you didn’t plan for.

This guide is built specifically for the Tsuyosa — not a general “how to measure your watch” article you have to adapt yourself. We’re going to confirm the exact lug width, talk about the bracelet swap, and walk you through the best strap materials for how this watch actually lives on your wrist. Let’s get that strap ordered with confidence.

Exact Lug Width Confirmed for the Citizen Tsuyosa

Here’s the short answer: the Citizen Tsuyosa uses a 20mm lug width. That’s consistent across the entire NJ0150 line, which covers the vast majority of Tsuyosa models you’ll find on the market today. If you own a standard Tsuyosa with the integrated-look bracelet, your strap measurement is 20mm at the lugs.

But there’s a catch that keeps tripping people up, and it’s worth addressing head-on. Some early or limited-edition references — particularly the NJ0151 and a few JDM variants — ship with a 19mm lug width. This is rare, but it happens. If you bought your Tsuyosa secondhand or from a non-standard retailer, you could be holding a 19mm watch without realizing it.

How to verify your reference: Flip the watch over. You’ll see the model number engraved on the case back — something like NJ0150-81X or NJ0151-81L. Look up that exact reference online or check the Citizen product page. If the listing says 20mm, you’re safe. If it says 19mm, adjust your strap search accordingly. The Tsuyosa isn’t a one-size-fits-all watch, and knowing your specific reference saves you the headache of a return.

Why This Model Matters as Its Own Page

You might be wondering why the Tsuyosa deserves a dedicated strap guide instead of just a generic “20mm watch strap” article. The answer is that 19mm-on-some-references quirk we just covered. Most watch enthusiasts are used to standard sizes: 18mm, 20mm, 22mm. When you’re shopping for a Tsuyosa and you hit a 19mm listing, it feels like a trap. It isn’t — but it’s enough to make you second-guess your purchase.

The Tsuyosa also has a slightly unusual case design. The lugs are short and curve downward aggressively, which means a thick, rigid strap can create a gap between the strap and the case. That’s not a problem with the factory bracelet, but it becomes one when you switch to a padded leather strap or a thick rubber option. A dedicated guide lets us address these fit quirks directly, so you’re not guessing.

Finally, the Tsuyosa is a popular modding platform. Owners are swapping dials, hands, and yes, straps. The aftermarket community has specific recommendations for this model, and we’re pulling those into one place. You’re not just buying a strap — you’re buying the right strap for your specific watch.

Bracelet End-Link Fit When Switching to a Strap

The Tsuyosa comes on a three-link bracelet with a polished center link and a butterfly clasp. It’s a decent bracelet for the price, but it has a specific end-link design that’s shaped to match the case contours. When you remove the bracelet, you’ll see that the end links are curved and slightly recessed into the lugs. That’s normal — but it means your strap won’t fill that space the same way.

Do you need adapters? Generally, no. The Tsuyosa has standard straight spring bars and standard lug holes. You don’t need a curved spring bar or a custom adapter to fit a strap. The strap will sit flush against the case between the lugs, and the gap left by the end link is cosmetic — it doesn’t affect function or security.

Spring bar size: The Tsuyosa uses standard 20mm spring bars with a 1.8mm tip diameter. Most aftermarket straps will include their own spring bars, but if you’re reusing the factory bars, make sure they’re not bent or worn. The factory spring bars are fine for strap use, but they’re designed for the bracelet’s thicker end links. You might get a slightly looser fit with a thin NATO strap — a thicker spring bar (2.0mm tip) can help if you notice play.

Best Material Options for the Tsuyosa

The Tsuyosa is a versatile watch. It’s an automatic with a 40mm case, 100 meters of water resistance, and a screw-down crown. That means it can dress up or down depending on the strap. But not every material works equally well with this case shape. Here’s what fits best.

Leather: The Dress-Up Choice

Thin, unlined leather straps work beautifully on the Tsuyosa. The short lugs and curved case mean a supple leather strap will wrap around your wrist without creating a stiff gap. Avoid thick, padded leather — it will stand away from the case and look awkward. Go for a 2-3mm thick calfskin or Horween leather for a clean profile.

NATO: The Casual All-Rounder

NATO straps are a natural fit for the Tsuyosa’s 100m rating. A single-pass NATO in 20mm will slide under the spring bars and sit flat against the case. The only issue is thickness: some premium NATOs are woven thick enough to create a slight bulge at the lugs. Stick with a standard thickness NATO (about 1.2mm) and you’ll be fine.

Rubber and Silicone: The Sport Option

The Tsuyosa isn’t a dive watch, but it can handle swimming and snorkeling. A tropic-style rubber strap or a fitted silicone option works well. Look for straps with a curved end that matches the Tsuyosa’s lug profile — straight-cut rubber can leave a gap. FKM rubber is more durable than silicone and resists UV damage better.

Canvas and Sailcloth: The Textured Middle Ground

Canvas straps are a popular choice for the Tsuyosa because they offer texture without bulk. Sailcloth, in particular, has a woven pattern that looks sharp and resists water. Again, watch the thickness — a 4mm canvas strap will feel stiff on the Tsuyosa’s short lugs. Aim for 2-3mm max.

Attachment Type Notes

The Tsuyosa has non-drilled lugs. That means there’s no hole through the side of the lug to access the spring bar from the outside. You’ll need to remove the strap or bracelet from the underside of the watch, using a spring bar tool. This isn’t difficult, but it’s worth knowing before you start — you can’t just pop a spring bar out from the side.

Quick-release compatibility: Most quick-release spring bars have a small lever that you push to release the strap. These work fine on the Tsuyosa, but the lever can sometimes catch on the case if the strap is very thin. Test the fit before you commit. If the quick-release lever touches the case when the strap is installed, you’ll scratch the polished finish over time. Standard spring bars avoid this issue entirely.

Comparison Table: Strap Materials for the Citizen Tsuyosa

This table gives you a quick reference for what works and what doesn’t. The key takeaway across all materials: keep it thin and keep it flexible. The Tsuyosa’s case design rewards straps that conform to its shape, not fight against it.

Final Thoughts on Strap Shopping for Your Tsuyosa

You now have the exact lug width (20mm for most, 19mm for a few references), the spring bar size (1.8mm), and the material guidance to make a confident purchase. The Tsuyosa is a watch that rewards experimentation — it looks good on almost anything, as long as you respect its short lugs and curved case profile.

Before you click “buy,” double-check your reference number. That’s the single most common mistake, and it’s the easiest to avoid. Once you’ve confirmed the width, pick a strap that matches how you actually wear the watch. Leather for the office, NATO for the weekend, rubber for the water — the Tsuyosa handles them all. Enjoy the swap.