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Trouble falling asleep, a sore back or shoulders every morning, or moving into a new place and wanting a fresh mattress — whatever the reason, searching for a mattress quickly gets confusing. Firmness ratings and coil construction vary by brand, and prices range from around ¥12,000 to over ¥70,000, making it hard to know where to start. Mattresses mainly differ in three ways: sleep feel from the core material and firmness (how well pressure is distributed), durability from the thickness and construction (coil count, density, resistance to sagging), and how generous the warranty or trial period is (return and exchange terms). Here we compare four products with a Spec Score built from five items: warranty, trial period, thickness, coil count and extras.
Our Picks — The Right One for You
Koala オリジナル
- Thickness21 cm
- FirmnessFirm (265 newtons)
- Recovery rate99.25%
A free 120-day trial and a 10-year warranty, 21 cm thick. Also #1 on the Spec Score.
Novilla 黒騎士 N-M02074
- Thickness26 cm
- FirmnessSlightly firm (in words)
At 26 cm, the thickest of the four. 406 pocket coils, a 10-year warranty and a 100-day trial.
GOKUMIN プレミアムスプリング
- Thickness20 cm
- Coil wire2.0 mm and 2.2 mm
496 pocket coils, the most of the four; the maker states 180N / 32D urethane. 8-year warranty.
ZINUS Prime Support
- Thickness25 cm
- Coil count450 (single)
- Warranty5 years (ZINUS official)
A 5-year warranty and a 120-day trial, both explicitly stated by the maker. 450 pocket coils (single), CertiPUR-US certified.
Pros and Cons of Mattresses
Here's what tends to satisfy people after replacing their mattress, and what's worth checking before you buy.
Pros
- Choosing a firmness that suits your body can make sleeping more comfortable (individual results vary)
- A build that considers airflow and pressure distribution is designed with night sweats and ease of turning over in mind (individual results vary)
- Many ship compressed and rolled, so you can unbox and set them up right at your door
Cons
- Since you can't lie down and test it before buying, how firm it feels varies a lot by person
- A new-mattress smell from the compressed packaging can linger, and some products need a few hours to a day of airing out after unboxing
- Thicker models come in larger, heavier packaging, so check your delivery access beforehand
How to Choose a Mattress: 7 Points
Here are 7 points to check before you buy. The figures in the diagrams come from the official and retail-page specs of the products in this article.
How to Read Firmness (N Values)
Firmness is sometimes given in newtons (N); a bigger number means firmer. But makers measure different things (the foam alone or the whole mattress), so figures cannot be compared across brands directly. Here, GOKUMIN (urethane, 180N) and Koala (265N) publish figures on their official pages.
Know the Constructions
What is inside changes how it supports you, how it breathes and how heavy it is. Of the four here, three combine pocket coils with urethane, and Koala is urethane foam with no coils.
Check the Thickness
A thicker mattress tends to feel less like you are touching the floor beneath. It also ships heavier, so check your delivery route.
Related pickNovilla 黒騎士 N-M02074（Thickness 5/5）
Look at the Coil Count (Coil Types)
With pocket coils, more coils tend to mean finer support. Products without coils (Koala) are left out. Figures are for the single size.
Related pickGOKUMIN プレミアムスプリング（Coil count 4/5）
Check the Warranty Length
A warranty covers defects and problems that appear during use. Check the length, and what is covered, before you buy.
Related pickKoala オリジナル / Novilla 黒騎士 N-M02074（Warranty 5/5）
Trial Period (Can You Return It?)
Firmness is hard to judge without lying on it, so a trial period with returns gives peace of mind. Only products that state a trial period are shown.
Related pickKoala オリジナル / ZINUS Prime Support（Trial period 5/5）
Extras and Assurances
Whether each has an antibacterial finish, a safety certification, a washable cover and compressed packaging, in one table.
Related pickKoala オリジナル / ZINUS Prime Support（Extras and assurances 4/5）
Spec Score Ranking
→ Swipe sideways to see the full table. Use the buttons to re-sort. Click a product name for details. You can also sort by clicking a column heading.
| Rank | Product | Buy (prices as of date shown) | ||||||
|---|---|---|---|---|---|---|---|---|
| 1 | KoalaオリジナルUrethane foam (no coils, 3 layers) | 4.25 | 5 | 5 | 3 | – | 4 | See on Amazon¥69,900See on Rakuten¥69,900Price as of 2026-09-17 · affiliate link · Opens the shop's site |
| 2 | Novilla黒騎士 N-M02074Pocket coil + high-resilience urethane | 3.65 | 5 | 4 | 5 | 2 | 2 | See on Amazon¥19,900See on Rakuten¥19,900Price as of 2026-09-17 · affiliate link · Opens the shop's site |
| 3 | ZINUSPrime SupportPocket coil (hybrid, coils + foam) | 3.45 | 2 | 5 | 4 | 3 | 4 | |
| 4 | GOKUMINプレミアムスプリングPocket coil + high-resilience urethane | 3.06 | 4 | – | 2 | 4 | 2 | See on Amazon¥23,998See on Rakuten¥21,698Price as of 2026-09-17 · affiliate link · Opens the shop's site |
Prices are as of 2026-09-17. They change with sales and stock, so please check the current price on the linked page.
A "–" in the table means the manufacturer and retail pages do not list that item (it is not counted in the score).
What each criterion means, and its weight
Each criterion is scored 1 to 5 and the overall score is the weighted average. The exact thresholds are in How the Spec Score Is Calculated.
- Warrantyweight 25%
- Warranty length (years)
- Trial periodweight 15%
- Days you can try it and return it. Only products that state a trial period are counted
- Thicknessweight 20%
- Mattress thickness (cm)
- Coil countweight 20%
- Number of pocket coils (single size). Products without coils are left out
- Extras and assurancesweight 20%
- Extras and assurances (starts at 1 point, +1 per listed item, max 5)
- Overall Spec Score
- Shown only when at least 4 of the 5 criteria have a score; the weighted average is taken over the criteria that do.
Compare 2 to 3 products side by side
Tick "Add to compare" in the table above and the products appear here (up to 3).
Product Notes
Koala・Urethane foam (no coils, 3 layers)
Koala オリジナル
- Warranty5/5
- Trial period5/5
- Thickness3/5
- Extras and assurances4/5
Good forBest for anyone who values a trial period and warranty for peace of mind
Good points
- A free 120-day trial and a 10-year warranty
- The cover comes off and can be machine-washed
- Uses CertiPUR-US certified urethane
Things to note
- The most expensive of the four (69,900 yen at the listing date, 2026-09-17)
- No coils, so look at other products if you want coil support
Novilla・Pocket coil + high-resilience urethane
Novilla 黒騎士 N-M02074
- Warranty5/5
- Trial period4/5
- Thickness5/5
- Coil count2/5
- Extras and assurances2/5
Good forBest for balancing sleep feel and durability between coils and foam
Good points
- At 26 cm, the thickest of the four
- A 10-year warranty and a 100-day trial period
- 406 pocket coils (single); bamboo charcoal, with antibacterial and deodorizing claims
Things to note
- Figures rest on the Rakuten shop page, not on a maker site
- Firmness is given in words ("slightly firm"), not as an N figure
ZINUS・Pocket coil (hybrid, coils + foam)
ZINUS Prime Support
- Warranty2/5
- Trial period5/5
- Thickness4/5
- Coil count3/5
- Extras and assurances4/5
Good forBest if a stated warranty and trial period both matter to you
Good points
- A 5-year warranty and a 120-day trial/return period, both explicitly stated by the maker
- CertiPUR-US certified foam; the retail page also lists an antibacterial and anti-mite treatment
- 25 cm thick with 450 pocket coils (single size)
Things to note
- As of 2026-10-10, the standalone Amazon listing for this mattress is out of stock with no restock planned. It's in stock on Rakuten
- The cover is not removable or washable
GOKUMIN・Pocket coil + high-resilience urethane
GOKUMIN プレミアムスプリング
- Warranty4/5
- Thickness2/5
- Coil count4/5
- Extras and assurances2/5
Good forBest for anyone who wants a firm, supportive feel
Good points
- The maker states the urethane as 32D density and 180N firmness
- 496 pocket coils (single), the most of the four
- An 8-year quality warranty from purchase
Things to note
- At 20 cm it is thinner than the Novilla
- An 8-year warranty, shorter than the 10 years of the Novilla and Koala
Still deciding? Check these in order
Still deciding? Check these in order
The Koala Original, with a 120-day trial and a 10-year warranty, is the candidate. The Novilla Black Knight (100-day trial, 10-year warranty) also fits.
The GOKUMIN, with 496 pocket coils and a maker-stated 180N urethane, and the 26 cm Novilla Black Knight are the candidates.
The ZINUS Classic pocket coil (model DST), the most affordable of the four at 11,990 yen on both Amazon and Rakuten (checked 2026-10-07), is the candidate.
Who Mattresses Are a Good Fit For — and Who Should Consider Other Options
As a category, these mattresses tend to work well for the following people.
Good fit if you...
- Want to choose a firmness that suits your body and rethink how you sleep (individual results vary)
- Want a build that considers airflow and weight distribution, for night sweats and turning over
- Want something that arrives compressed and can be set up from the front door without help
Consider other options if you...
- Are uneasy about buying without lying on it first and would rather try one in a shop
- Are happy with your current mattress's firmness and durability
- Have a delivery route or a space that cannot take a thick, heavy model
Commonly Cited Complaints, and How to Handle Them
Across mattresses in general, a point commonly raised is that a new-mattress smell from the compressed packaging is noticeable right after unboxing. Airing it out for a few hours to a day in a well-ventilated room usually reduces the smell significantly. Another commonly raised point is that the mattress feels firmer or softer than expected — an outcome that's hard to avoid given how much firmness perception varies by person. Checking the return/exchange terms and trial period in advance, or trying a similarly firm mattress in a physical store first if possible, can help reduce the chance of a mismatch. Thicker models can take longer to fully expand after being compressed, so even if it doesn't reach its full thickness right after unboxing, it's worth waiting about 24 hours before judging the feel.
Best Pick by Situation
If you want to balance sleep feel and durability between coils and foam, go with the Novilla Black Knight. If you want a firm, supportive feel, go with the GOKUMIN Premium Spring. If you value peace of mind through a trial period and warranty, go with the Koala Original. If you want to keep the cost down and just try one out, go with the ZINUS Classic Pocket Coil (DST).
First Steps After You Buy
Once you open the packaging, take the mattress out in a well-ventilated room, lay it flat, and let it sit for a few hours to a day. Compressed mattresses often haven't fully returned to their true thickness right after unboxing, and leaving them for about 24 hours brings them closer to their intended thickness and firmness. Odors can transfer from the packaging material, so airing it out with the windows open helps reduce any lingering smell. If you're using it on a bed frame, a slatted base or a breathable frame helps prevent moisture buildup and keeps the sleep feel more consistent. For products with a warranty or trial period, it's worth noting the terms (how to apply, the deadline) at the time of purchase so you're ready if you ever need them.
How the Spec Score Is Calculated
Each criterion is scored from 1 to 5, and the overall score is the weighted average. We use the manufacturer's official figures; where the official site could not be read, we fill in from Amazon, Rakuten Ichiba, Kakaku.com and similar retail or comparison pages (only pages that match the exact model number). A criterion with no published figure is left out and the average is taken over the rest (for care and features, only items that are actually listed earn points).
| Warranty (25% weight) | Warranty length (years) 10 years or more = 5 / 8+ = 4 / 6+ = 3 / 5+ = 2 / below = 1 |
|---|---|
| Trial period (15% weight) | Days you can try it and return it. Only products that state a trial period are counted 120 days or more = 5 / 100+ = 4 / 60+ = 3 / 30+ = 2 / below = 1 |
| Thickness (20% weight) | Mattress thickness (cm) 26 cm or more = 5 / 23+ = 4 / 21+ = 3 / 18+ = 2 / below = 1 |
| Coil count (20% weight) | Number of pocket coils (single size). Products without coils are left out 500 or more = 5 / 480+ = 4 / 450+ = 3 / 400+ = 2 / below = 1 |
| Extras and assurances (20% weight) | Extras and assurances (starts at 1 point, +1 per listed item, max 5) Antibacterial / deodorizing finish / safety certification (e.g. CertiPUR-US) / washable cover / delivered compressed |
Summary
This comparison uses published specs, not how the mattresses feel in use. Feel varies from person to person, so choose with the warranty and any trial period in mind.
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Update history
Show update history (2)
- Rewritten on the new template (Spec Score, product detail pages).
- Display improvements (summary at the top, ranking cards, sortable comparison table with side-by-side compare, in-page navigation). Scores, prices and links are unchanged.