PD-KB400KTWN — Blank white keycap set for HHKB Professional series

The PD-KB400KTWN is PFU's genuine replacement keycap set for English-layout HHKB Professional keyboards. It ships as 60 blank white keycaps plus a puller, letting you reset the look and feel of the board without replacing the keyboard itself.

This article covers exactly which models it fits, how it differs from the other PFU keycap sets, and the mistakes buyers actually make.

Overview

Two groups get real value here. First, owners whose English-layout HHKB has developed shiny or yellowed caps after years of use.

Second, users who have remapped their layout and now find the factory legends actively misleading. In both cases the board works fine and only the surface has degraded, so a keycap swap solves it for a fraction of a new keyboard.

Inside the box: 60 keycaps identical in spec to the factory-installed ones, a keycap puller, and a manual with the replacement procedure and a key layout chart. The material is listed as plastic; HHKB caps are generally understood to be PBT, and because this version is blank there is no printing to wear off in the first place.

That is a quiet long-term advantage over printed sets.

Amazon.co.jp reviews stood at 103 reviews averaging 4.7 out of 5 — a 94% positive score — as captured on June 1, 2026.

That is not a huge sample, but it is steady for a narrowly scoped first-party replacement part.

Why choose blank caps

The benefit of blank keycaps is not only aesthetic. The practical win is that they eliminate the mismatch between what is printed and what the key actually types.

HHKB is designed around Fn layers and keymap customization, so the longer you use one, the more likely the legends are simply wrong. With no legends, there is nothing to contradict.

The downside is just as concrete. If you still glance down to find [, ], \, ~, or your Fn arrow cluster, blank caps will slow you down for a while.

The honest test is whether you already touch-type the English HHKB layout in daily work.

Blank caps also make a shared machine painful. Treat this as a set for a strictly personal keyboard.

Compatibility Guide

This set is for English-layout HHKB Professional series models only. Supported models:

• HHKB Professional
• HHKB Professional2
• HHKB Professional2 Type-S
• HHKB Professional BT
• HHKB Professional HYBRID
• HHKB Professional HYBRID Type-S
• HHKB Professional Classic

The failure cases, in order of how often they bite:

Japanese-layout boards will not work. JIS layout differs in both key count and key widths, so the set physically does not map.

Japanese-layout sets are sold separately under the PD-KB420 model numbers. Check for the 変換 / 無変換 keys before ordering.

Other manufacturers' keyboards are out. HHKB uses electrostatic capacitive switches whose keycap stems differ from the common Cherry MX design.

You generally cannot fit these caps to an MX board, nor fit MX caps to an HHKB. "It's 60 keys, so it must fit a 60% board" does not hold.

Anything not on the list above should be assumed unsupported. Model lines using a different switch mechanism are a different product entirely.

If your model name does not match the list exactly, confirm on the product page before buying.

The set contains 60 keycaps, a full English layout. Individual keys are not sold separately, so even a single broken cap means buying the whole set again.

Product Info

On pricing, every figure below is a captured snapshot, not a current price. Amazon.co.jp listed it at ￥6,600 as captured on June 1, 2026.

On eBay US it showed $82.89 as captured on July 15, 2026 — well over double the Japanese domestic level, which is what import and resale markup looks like.

If you can buy domestically, do.

One more caveat worth passing on: an automatically collected domestic listing showed ¥29,000, but that appears to be a hometown-tax (furusato nozei) return-gift listing rather than the standalone part, and it is an order of magnitude off the roughly six-thousand-yen street price. Searching the model number can surface gift listings and overseas resellers side by side, so check the listing type before comparing prices.

Confirm the current price on the product page in any case.

How it differs from the other PFU sets

PFU sells several keycap sets for HHKB, and picking the wrong one means it simply will not fit. Three axes decide it.

Layout (English vs Japanese) — a hard physical constraint. This one is English only.

Printing (blank vs center-printed) — center-printed sets place the legend in the middle of the cap. If you want legends but a different color from stock, that is the branch to take.

Color (white, wisteria, and so on) — this set is white. Match the model-number suffix to the color you want.

Choose PD-KB400KTWN only when English layout, blank, and white are all true for you. If any one of those is off, look for a different model number instead.

Replacement and real-world feel

No special skill is required. Hook the supplied puller on opposite corners of the cap and lift straight up; prying at an angle stresses the switch.

Do not pull all 60 caps at once — keep the layout chart from the manual in front of you and work a few keys at a time.

Wide keys such as the space bar are built differently, so follow the manual for those rather than treating them like ordinary caps.

As for typing feel, these are the same caps the board ships with, so nothing should change. If your goal is a better or quieter typing experience, this set is the wrong purchase — look at Type-S hardware instead.

Best Use Cases

• Long-term English-layout HHKB owners with shiny or yellowed caps. A like-for-like refresh that leaves the typing feel untouched, for a tiny fraction of a new board.
• Users running a custom keymap. Removing legends removes the contradiction between printing and behavior — a genuine usability gain, not just a look.
• Confident touch typists on the US layout. You lose essentially nothing by going blank.
• Minimal desk setups. White blank caps carry the least visual information of any option here.

Before You Buy

Verify your layout first. The most common failure is owning a Japanese-layout HHKB and buying the English set.

The 400-series model numbers are English layout, the 420-series are Japanese. Confirm against your own board before ordering.

This is not a cheap custom keycap hobby. Because the stems are not MX-compatible, inexpensive aftermarket sets are not an option for HHKB.

The roughly six-thousand-yen price is the price of the only real choice; hunting for alternatives usually costs more in time than it saves.

No individual keys. Break one cap and you buy sixty. Some owners keep a spare set for that reason, but that is money spent up front.

Keep your original caps. They are the only way back if blank turns out not to suit you, and having the stock caps helps at resale time.

Listing data and prices can be wrong. As noted, model-number searches can surface gift listings and overseas resellers with wildly different prices, and marketplace metadata (manufacturer, model number, ASIN) occasionally belongs to a different product.

Before ordering, confirm visually from the product photo and title that you are getting English layout, blank, white, 60 caps. That one check prevents almost every wrong-layout purchase.

Warranty. Check official PFU information for warranty terms.

This is closer to a consumable part than to the keyboard itself, so do not assume the same coverage.

FAQ

Q. Will it fit a Japanese-layout HHKB? A.

No. Key count and key widths differ.

Japanese-layout sets use the separate PD-KB420 model numbers.

Q. Can I use these on another mechanical keyboard? A.

Assume not. HHKB's capacitive switches use a stem shape that differs from Cherry MX, so swapping either direction generally does not work.

Q. Does swapping change the typing feel or sound? A.

It should not — these are the same caps the board ships with. For a different feel or quieter operation, look at the hardware (Type-S) instead.

Q. Can I buy a single key?
A. No. Individual keys are not sold; it is the 60-piece set only.

Q. Will blank caps hurt my accuracy? A.

Barely, if you already touch-type the US layout. If you still look down for symbols or layer keys, expect a slow period — a center-printed variant may suit you better.

Q. What does it cost? A.

￥6,600 on Amazon.co.jp as captured on June 1, 2026.

Prices move and some listings are far off the street price, so check the product page for the current figure.

Product Disclosure (Amazon)

• Manufacturer: HHKB
• Seller: PFUダイレクト
• Fulfilled by: PFUダイレクト
• ASIN: B00FQ5FZNQ
• Note: This article covers a manufacturer-made product based on Amazon listing details.