Yasuhiro Hashimoto: Elegance Over Difficulty

Quick answer: Yasuhiro Hashimoto is a Japanese puzzle designer and one of the most admired people working in the field. He has entered the Nob Yoshigahara Puzzle Design Competition four times across a decade and been recognised every time, culminating in the 2025 Puzzlers' Award, the one prize there that puzzlers vote for themselves.

Best for: solvers who want to understand why this community talks about elegance rather than difficulty.

There is a kind of designer who earns respect by being brutal. Levels in the hundreds, moves you have to count, a reputation built on how many people give up.

Hashimoto is the other kind, and he is held in higher regard for it.

Four Entries, Four Recognitions

The Nob Yoshigahara Puzzle Design Competition at the International Puzzle Party is the closest thing this field has to a formal honour. Hundreds of designs are entered. Most get nothing.

• 2015 — 4L. Jury Honorable Mention.
• 2019 — Tetra Spinner. Top-ten vote getter for the Puzzlers' Award.
• 2023 — Karakuri Packing. Jury Honorable Mention.
• 2025 — Diagonal Twins. Puzzlers' Award and Jury Honorable Mention.

Four entries, four times recognised. Designers who enter that competition regularly will tell you how unusual that is. He is not flooding it either: roughly one puzzle every few years, each time something he has decided is worth showing.

Watch: Tetra Spinner by Yasuhiro Hashimoto

This is the 2019 entry, and it is the clearest look at how he thinks. Five tetromino pieces, a tray, and a plexiglass frame that has to be slid out of the way before the pieces that overhang can be loaded. It is not one of ours, and watching twelve minutes of it is the fastest way to understand why the word people reach for is elegant rather than hard.

The Award Puzzlers Vote For Themselves

The 2025 result deserves separating out, because of how that particular prize is decided.

A judging committee picks almost everything at the competition. The Puzzlers' Award is voted on by the attendees, which is to say by several hundred of the most experienced solvers and collectors alive, after they have spent days handling everything on the table.

Diagonal Twins took it, and a Jury Honorable Mention alongside. The specialists admired it, and the people who solve puzzles for pleasure chose it as their favourite thing in the room.

What Solving One Is Actually Like

Two of the most-read reviewers in the hobby have written about his puzzles, and neither reaches for the word difficult.

Allard Walker on Karakuri Packing, his 2023 entry: a quick count convinces you there is more than enough space in the box, and then that little strip across the top turns out to be quite confounding. He got one almighty A-Ha buzz out of it that lasted for ages, and called it a favourite of recent years.

Kevin Sadler at PuzzleMad on Diagonal Twins: he watched a stream of experienced puzzlers try and fail, needed about an hour and a half himself, and concluded that it is such a simple idea and yet so tremendously beautiful in its execution.

That is the pattern. Anyone can make a puzzle nobody solves: add pieces, add moves, tighten the tolerance until it binds. What Hashimoto does is find a problem you can state in one line, that looks like it should take a minute, and that then refuses you for an hour without ever feeling unfair. Nothing is hidden. There is no trick you could not have seen.

The One You Can Buy

The 4L Puzzle is his 2015 entry, the one that first took a Jury Honorable Mention. Four identical L-shaped pieces and a shallow box, and the volume works out exactly.

The catch is the opening. A lattice panel covers one corner, so you can see the space but cannot lower anything into it. Three pieces go in almost without thought. The fourth has to be worked in sideways, beneath the covered section, in an order that only functions one way.

Ten years later Diagonal Twins is doing the same thing with two pairs of pieces and a strip across the top. The restriction is the idea, and it has been the idea the whole time.

It carries a straight five stars here, and the two reviews worth quoting say the same thing from opposite ends. Gregory Clayborne, who keeps a curio cabinet for his best puzzles, gave it a prominent spot: it is that good. The solution path on it is just brilliant. Everyone should experience this masterpiece. Hiro F, who had solved this type of packing puzzle before and considered himself fairly good at it, still needed about an hour: it looks simple, but it is actually quite tricky.

A collector calling it a masterpiece and an experienced solver admitting it took an hour. That is the whole case for Hashimoto in two sentences, written by customers rather than by me.

Dr. Volker Latussek is the other designer here who treats a container as something to design rather than something to ship in.

Diagonal Twins, and the One We Do Have

People arrive on this site searching for Diagonal Twins. We do not carry it, and it is worth being straight about that.

What we do have is its descendant. MINIMA Slider is Frederic Boucher's response to it: five pieces, one box, exactly one solution, built on the same conviction about openings. It had its world debut here. If Diagonal Twins is what brought you, that is the closest thing on the shelf, and the lineage is deliberate rather than accidental.

Which Hashimoto Puzzle to Start With

There is one place to start, which makes this simple: the 4L Puzzle. Everything of his we stock sits in the Yasuhiro Hashimoto collection, the form is packing puzzles, and the wider category is mechanical puzzles.

Frequently Asked Questions

Who is Yasuhiro Hashimoto?

A Japanese puzzle designer widely regarded as one of the best working today. He designs packing puzzles of unusual elegance and releases few of them. He has been recognised at the Nob Yoshigahara Puzzle Design Competition four times, winning the 2025 Puzzlers' Award, the only prize there chosen by attending puzzlers rather than by judges.

What awards has Yasuhiro Hashimoto won?

Jury Honorable Mentions for 4L in 2015 and Karakuri Packing in 2023, a top-ten Puzzlers' Award vote for Tetra Spinner in 2019, and both the Puzzlers' Award and a Jury Honorable Mention for Diagonal Twins in 2025.

What is the Diagonal Twins puzzle?

Two pairs of identical pieces packed into a box with a slightly restricted opening. We do not carry it, but MINIMA Slider by Frederic Boucher was built directly from the idea.

Which Yasuhiro Hashimoto puzzle can I buy here?

The 4L Puzzle, four L-shaped pieces into a box with a covered corner. Rated Expert, and the difficulty sits almost entirely in the final piece.

What is a restricted opening packing puzzle?

One where the container's opening is deliberately blocked or undersized, so pieces cannot simply be lowered in. The solution is an order and a set of angles rather than an arrangement. Dr. Volker Latussek is the other designer here who works this way.

For another packing designer working at the top of the field, see Alexander Magyarics and Goh Pit Khiam.