This article covers the PFU HHKB Professionalシリーズキートップセット日本語配列中央印字藤 PD-KB420KTLPC — which HHKB models it fits, how the swap actually goes, and who should skip it.
Overview
The PFU HHKB Professional Series Keycap Set, Japanese Layout, Center Printed, Fuji (PD-KB420KTLPC) is a replacement keycap set made specifically for HHKB Professional series keyboards. As the fourth installment of the "HHKB Color Keycap Project," it uses a pale wisteria purple inspired by the graceful fuji flower.
The package includes 69 keycaps, a keycap puller, and an instruction manual.
To be clear up front: this is not a performance part. It changes how your HHKB looks, not how it feels — typing feel comes from the capacitive switches in the board itself.
On Amazon.co.jp it holds 4.6 out of 5 stars across 57 reviews (92% favorable, captured June 2026), which suggests buyers get what they expect.
That said, if you can't immediately confirm whether your HHKB is a Japanese-layout board, stop and check the label and legends first. That single check prevents the most common purchase mistake with this product.
Compatibility Guide
This set fits Japanese-layout HHKB Professional models only — six of them:
| Compatible model | Note |
|---|---|
| HHKB Professional JP | Wired, JP layout |
| HHKB Professional JP Type-S | Silenced |
| HHKB Professional BT | Bluetooth |
| HHKB Professional HYBRID | Wired + wireless |
| HHKB Professional HYBRID Type-S | Silenced HYBRID |
| HHKB Professional Classic Type-S | Wired, silenced |
The manufacturer states plainly that the set is compatible only with Japanese-layout HHKB Professional models and not with the HHKB Studio series. Studio uses a different switch and keycap system, so visual similarity means nothing here.
The second trap is layout. US and JP HHKB boards differ in key count, key widths, and legends — a 69-key JP set will not line up on a US board around the spacebar and the conversion keys.
US-layout owners need the English-layout release from the same project instead.
So unlike a CPU or GPU, compatibility here reduces to two questions: is it a Professional (not Studio), and is it Japanese layout? Answer both and the caps drop straight on.
Product Info
The set launched in late 2025. On Amazon.co.jp the price was ￥9,240 as captured in both June 2026 and August 2026 — two readings two months apart agreeing, which suggests it sits stably near list price.
Stock and sales still move it, and this article will not update itself, so check the product page for the current price. PFU Direct also carries it.
Key specs: Japanese layout, center-printed legends, 69 keys, wisteria purple (藤), with a keycap puller and manual included. Center printing looks noticeably different from the upper-left legends on older HHKB caps — cleaner as a full set, but visibly inconsistent if you mix only a few caps into an existing board.
Reviews stand at 57 on Amazon.co.jp, 4.6 of 5 (92% favorable, captured June 2026).
The low review count reflects a model-specific accessory, not weak reception. The overseas marketplace listing (eBay) returned no concrete price — only "See listing" — so treat this as a domestically distributed first-party accessory.
How the Swap Goes
Photograph the board from above first. Pulling all 69 caps and then wondering where one belongs is the classic mistake; one photo solves it.
Pull straight up, slowly. Angled pulls scratch cap sidewalls and neighbors.
Use the included puller and don't pry. 3.
Work in small groups. Swap a few caps at a time rather than stripping the whole board.
Leave spacebar and Shift for last. Wide keys bind if tilted; handle them with open space around them.
Keep the original caps. You may want them back, and a complete set of stock caps helps at resale.
PFU notes that replacement is done at your own risk and that scratches can occur. Read the manual before starting.
Versus the Alternatives
Compared with third-party sets, the real difference isn't price — it's whether alternatives exist at all. Generic PBT sets ship 100+ keys for a few thousand yen, which makes ￥9,240 (captured August 2026) look steep per key.
But HHKB Professional caps follow HHKB's own layout and dimensions; Cherry MX-oriented sets simply don't mount. There is no cheaper equivalent to compare against, so if you want a different color on a JP-layout HHKB Professional, this project is effectively the answer.
Within the project, comparison is real: Sakura, Wasabi, and Tanpopo came before, and Fuji is the fourth. Swap everything for a uniform look, or recolor only the modifiers.
If you mix sets, confirm they share the same center-printed legend style first.
Best Use Cases
- JP-layout HHKB Professional owners who want a new look without replacing the board. The low-saturation purple stays office-appropriate.
- Customization enthusiasts who want to combine Fuji with Sakura, Wasabi, or Tanpopo for a mix that no stock board has.
- Buyers who insist on first-party parts. Legend quality and exact cap dimensions are where official sets win, and HHKB's layout is unusual enough that this matters.
- People who specifically prefer center-printed legends — the difference is bigger in person than in photos.
It is the wrong purchase if your goal is better typing feel or quieter keys. That lives in the board (Type-S, dampening), not the caps.
Before You Buy
Layout and series verification comes first. JP-layout HHKB Professional only — not US layout, not HHKB Studio.
"It's an HHKB, so it'll fit" turns into unusable inventory.
Replacement is at your own risk. Even with the puller, off-axis force scratches caps and switches.
Wide keys need the most care. If that worries you, weigh the cosmetic payoff against the risk before ordering.
No single-key sales. Wanting one purple Enter still means buying all 69 caps, which is poor value for a single accent.
It is not cheap. ￥9,240 as captured in August 2026.
Fair for first-party quality and a limited color, but nothing about the keyboard's function improves.
Color reads differently in person. Pale purples shift with lighting — expect it to look bluer or greyer than product photos under some desk lamps.
Check the listing data yourself. With niche first-party accessories, listing prices and marketplace figures sometimes attach to a different product (here, the overseas marketplace entry returned no real price at all).
Match the product images, title, and the model number PD-KB420KTLPC before you check out.
FAQ
Q. Will it fit a US-layout HHKB? A.
No. This is Japanese layout only; US owners should look for the English-layout release from the same project.
Q. Does it fit HHKB Studio?
A. No. PFU explicitly lists Studio as incompatible.
Q. Does typing feel change after swapping? A.
Essentially no — the capacitive switches determine feel. For quieter typing, look at Type-S boards instead.
Q. How many keys, and is anything missing? A.
69 keys, covering the full layout of supported models. Individual keys aren't sold separately.
Q. Can I go back to the stock caps?
A. Yes. Keep the originals and photograph the layout beforehand, and reverting is straightforward.
Q. How is it rated?
A. 4.6 of 5 stars from 57 Amazon.co.jp reviews (92% favorable), captured June 2026.
Product Disclosure (Amazon)
- Manufacturer: HHKB
- Seller: PFUダイレクト
- Fulfilled by: PFUダイレクト
- ASIN: B0FXLTLWGS
- Note: This article covers a manufacturer-made product based on Amazon listing details.
