Saturday, December 31, 2022

Looking Back to 2022

Hello puzzle lovers!

It's time to look back on this year.

We Have released the following 12 kinds of mechanical puzzles in 2022.

19th February - Puzzle Turbine and Splitted 12

We had been temporarily closing our web shop since near the end of 2021. After the shop was resumed, two types of high-level burr puzzles with slightly unusual shapes have been released.

23rd April - Bubble Universe

Juno says it was very difficult to produce this two-layer packing puzzle because of the small glued area of the pieces and the tight tolerances.

22nd May - Mittan

This is the Jury Grand Prize winner puzzle of the 2022 Nob Yoshigahara Puzzle Design Competition. We received many personal emails from cat-loving customers.

10th July - Crooked 6 Board Burr #2 and Partially Crooked 6 Board Burr

The assembled shape of both puzzles looks like a regular 6 board burr, but when you start playing the puzzles, it feels very strange.

7th August - Card Case

We didn't dare mention it at the time of release, but there is a maze on either side of the light-colored slider of the puzzle.

18th September - Kumikisaurus

This is our first-time animal-shaped burr puzzle. It sold much faster than we expected.

6th November - Ovoloid

Five kinds of timber species, Bubinga (Sap wood), Tasmanian Myrtle, Fijian Mahogany, Camphor Laurel and Wenge are used for this very difficult burr puzzle.

25th December - Euroka 10x3, Half Splitted 12, and Pseudo Stretchy 12

Since pluredro in Esperanto means polyhedron, we always wanted to have polyhedral shaped puzzles in stock, but the Euroka 10x3 sold out in almost a day. The remaining two were added to Juno's invention of burr puzzles consisting of six 2x2 pieces and six 3x1 pieces.

How many puzzles have you played already?
We aim to make more fun puzzles tickle your intellectual curiosity.

We wish you and your family the best for the next year!

Sunday, December 25, 2022

Three new burr puzzles, 26th Puzzle Auction Results

We are going to release three kinds of burr puzzles, Euroka 10x3, Half Splitted 12 and Pseudo Stretchy 12, today. It's been a while since we sold out of polyhedral puzzles in stock, so it's time to add new one.

Three puzzles were put up for charity auction, with total puzzle sales reaching a staggering $1,841.09! As promised, half of the puzzle sales were donated to BirdLife Australia to help save the future of Australia's native birds. 

In warm appreciation of your loyalty during the past year, we extend our very best holiday wishes to you and your loved ones. 

May your Christmas and new year be filled with happiness and success.
We'll see you again next year!

Thursday, November 10, 2022


I was saddened and shocked to hear of the passing of my old friend Eric Fuller.

It had been a long time since Eric first contacted me by email. In 2005, Eric was very early in his puzzle making business and he wanted to know if my puzzle designs could be used in his business. I never heard his name until then but anyways, I replied OK to him because there was no reason to deny his offer, and I thought that he was gentle and polite.

One day, I received a parcel from Eric containing Two by Three puzzles. To be honest, I thought his work was not that much better than similar burr puzzles made by Japanese craftsmen. The puzzles that Eric made were not coated and the tolerances were a bit too loose, and I thought to myself, if business can be done with such things, the US must be easy. In hindsight, he may not have owned the superior machines and tools that he does today.

Each time he sent me a designer's copy of a puzzle he made, the quality improved. He always cared about the puzzle designers and was willing to pay royalties.

My first face to face encounter with Eric was at an IPP (International Puzzle Party). He found me and started telling me that he would like to produce more of my designed puzzles using exotic timber. He looked very shy and humble, perhaps because he didn't have a Mohican hairstyle back then. My wife and I often call mischievous cockatoos that come to our backyard Eric, by the way.

I left Japan with my wife in 2011 and moved to Australia, and when I applied for a work visa in 2013, I asked Eric if he could write a reference letter for me. Eric immediately responded to my request, knowing that my business sponsor (Mr Puzzle) and I would be a potential competitor for his business. I thanked him and told him I should buy him a glass of beer in the future. Additionally, when my wife and I started our puzzle business, Eric was kind enough to give us information on what kind of circular saw blades, dado blades, and coatings he used. Thankfully, I had the opportunity to meet him at the IPP in Paris in 2017 and had the chance to return the favor.

I continued to collaborate with Eric and he has proven that we can share this puzzle world. He promised to show me his workshop if I had the opportunity to visit the US. The last time I received an email from Eric was only a month ago. He was discussing about his future project involving a puzzle I had recently designed.

He was too young. It was a great loss to his family, friends and the puzzle world. Rest in peace my friend.


Sunday, November 6, 2022


Our latest product is Ovoloid, very complex level 21 burr puzzle. Five kinds of wood were used to create this puzzle: Bubinga (sap wood), Tasmanian Myrtle, Fijian Mahogany, Camphor Laurel, and Wenge, and their textures make for a fascinating puzzle.

This will be our last puzzle to be released towards Christmas. Several of our puzzle products are in progress, some of which will be released near the end of 2022.

Happy Puzzling!

Monday, September 19, 2022

Kumikisaurus, 25th Puzzle Auction Results

We have released the dinosaur-shaped burr puzzle Kumikisaurus yesterday. The burr offers a unique level 10-13 solution and reasonable difficulty. At the moment, we have only five in stock, so the puzzle may sell out soon.

Our 25th puzzle auction event ended on 17th September. We put up three 2nd grade Mittan and three Penta Cuboids.

The total sales amount reached a stunning AUD $3,645. As promised, we donated half of the sales, AUD $1,825, to the local food bank. We usually donate to animal welfare organizations, but under COVID-19 and high commodity prices, we decided to contribute to the local food bank this time.

Here is the receipt for the donations.

Usually, I would be delighted with the total sales, but this was different.

The winner, who was supposed to get two puzzles, suddenly said he didn't want to pay the amount he had bid. He entered the wrong amounts and didn't notice them until he received congratulatory notices. Although there must be chances to check his auction activities, he probably hadn't visited the auction pages until auctions ended. It was too late to receive his request to change or cancel his proxy (automatic) bidding amount.

We cannot sell puzzles to someone without the intention to pay for the winning bid, so we have cancelled his bids. After that, we thoroughly checked the bidding history for the auctions, including the one the man did not bid for, to find the reasonable winning amount not affected by the cancelled bidding. It was AUD $603 to guarantee fairness to all auction bidders.

Then, we offered two people in the second and third positions in the Mittan auctions if they wanted to buy the puzzle for AUD $603. Fortunately, both of them were happy with the proposal.

We also offered AUD $242 discount to the winner whose winning bid was AUD $845. Although those who made unintended high bids did not join this auction, it was reasonable to consider it was also affected by the other auction results since many bidders were chasing three (almost) identical puzzles.

Our actual auction sales amount was reduced to AUD $2,866. Our donation to the food bank was AUD $1,825, which is tax deductible, but we still pay a hefty tax on sales. Considering the transaction fee to the shop system cost for the auction App, and so on, our income through these auctions will be around AUD $800. Thankfully, the winning bids of three Penta Cuboids became quite high, but without that, we might have ended up in the red.

It's not only the money. We had to spend extra time solving this problem. If you have experience running an online shop, you may know it's not easy to handle something irregular.

Running a business isn't easy. It's the same as running in a grassy meadow; you cannot tell where the pit hole is.

Sunday, August 7, 2022

Card Case

This is our seventh puzzle product released this year. Juno designed the new puzzle box Card Case to force two of our CNC routers to work hard while he was doing detailed work.

Although it is not a sequential discovery puzzle, it is a different kind of challenge. You will quickly learn what you need to do to solve the puzzle, but it may take some time before you reach your goal.

Happy Puzzling!

Monday, July 11, 2022

The 24th Puzzle Auction Results, new puzzles

The 24th Puzzle Auction, which was held for the first time on our own website on July 9, has been successfully completed. The bidding results are as follows:

The total sales amount was AUD $376.00, so we rounded it up and donated AUD $190.00 to Save The Bilby Fund.
Here is the receipt.

The Bilby is not as famous as kangaroos or koalas, yet we hope this beautiful creature will be able to escape extinction.

We started selling the product versions of two new puzzles, the same kinds as auction puzzles yesterday morning.

There are two new puzzles; one is Crooked 6 Board Burr #2. This is a fun, "what the heck is going on" kind of burr puzzle. The other is Partially Crooked 6 Board Burr, a hybrid design of normal 6 board burr and crooked 6 board burr.

Hope you enjoy our new puzzles!

Tuesday, July 5, 2022

24th Puzzle Auction and Mittan Puzzles' 2nd Chance

24th Puzzle Auction and Mittan Puzzles' 2nd Chance

We have started auctions!

Pluredro Auction

Before releasing two kinds of board burr puzzles on Sunday 10th July at 07:00 a.m. (Brisbane time), we started auctions on our website.
We used to hold our puzzle auction on eBay but decided to have auctions on our website. We hope that the auction system works flawlessly and becomes beneficial to our customers. The winning auction items can easily be combined with our regular products and shipped together.

This time, we have put up six puzzles in total, test version and second-grade puzzles for auctions. The start amount is AUD $1.00 as usual. We will donate half of the total sales amount to the Save the Bilby Fund to save the precious marsupial of the Australian outback.

Regarding our new board burr puzzles, please visit the following "Upcoming puzzles" page for information about our new puzzle. The puzzle information on this page will be available until before the puzzles are released.

Mittan puzzles' 2nd chance

We have kept several 2nd-grade Mittan puzzles that we did not put on our web shop. Please contact us if you are interested in purchasing one of them at AUD $720, the same price as the product versions. We will be offering the sale to those who meet at least one of the following conditions.

1) You are an invitee to the IPP.
2) You have met and talked with Juno in person.
3) You currently own more than 20 Pluredro products.
4) You can convince us that you are a cat lover.

The kept Mittan puzzles will be sold one by one after ensuring that the product versions of Mittan puzzles safely reach our customers. Even if you can buy one of the kept puzzles, it may be another week or more before you hear from us.

Happy Puzzling!

Monday, May 16, 2022

23rd Puzzle Auction Results etc.

Our 23rd puzzle auction event has ended on 15th May. We put 10 Pine versions of Mittan puzzles up for auction this time and the total sales amount reached stunning AUD $10,352! Thank you for your bids. Here the captured image of the auction results.

To donate a half of the sales amount, we were excited and headed to the animal shelter. It is easier to donate online, but by doing it in person, we have a good excuse to meet our fluffy friends at the animal shelter.

There were lots more cats waiting for their permanent family at the animal shelter compared to the beginning of the pandemic. 

We played with them, donated the money raised at the auction, and went home. Here is the receipt of the donation.

Product versions of Mittan puzzle will be available very soon. The auction results and the interest we have received indicate that the puzzles may sell out quickly. Please refer to the store's top page for tips on how to speed up the purchase process so that you can get your favorite color of Mittan puzzle on the day of release.


Sunday, May 8, 2022

New SD Puzzle, "Mittan" and 23rd Auction

Juno and I know many people love sequential discovery puzzles (from now on, this is called "SD puzzle"). We have been working hard on our new SD puzzle, yet it has been a long time to accomplish it. Now, we finally finished making our new SD puzzle: Mittan.

We are going to release Mittan on our Pluredro Shop on Sunday 22nd May 06:00 (A.M.) Brisbane time. Please visit the next "Upcoming puzzles" page for information about our new puzzle. The puzzle information on this page will be available until shortly before the puzzles are released.

You may wonder what Mittan is. Mittan is our beloved ginger cat that was brought from Japan. Her paws looked like mittens, and her foster mother named her Mittan that sounds almost like a Japanese-speaking English mittens. People who know about cats well tend to assume Mittan is a male cat, but Mittan is female. Male ginger cats are more common than female cats; roughly three males to one female ginger cat. She was a stray cat in Fuji city, where there is a famous mountain, Mt. Fuji. A friend of mine rescued her, and after that, we adopted her in 2009. We had some difficulties bringing her and other cats from Japan to Australia. She had to stay in quarantine for one month. Here are some pictures of Mittan.

We thought that we had produced many geometric designs of SD puzzles, and it is probably a good opportunity to make something of a concrete design. That is why Juno had decided to make a cat puzzle. Juno tried to imitate Mittan's face as much as possible. I believe the puzzle looks like Mittan; well, what do you think? The face of Mittan puzzle is made with Zebrano. I think Zebrano is a very suitable material for describing a pattern of a ginger cat. (or should we have made a zebra instead?)

Mittan loves to eat fish. So, the final cavity contains a small figure of Taiyaki. Taiyaki is a Japanese traditional fish-shaped cake filled with azuki sweet red bean paste.

We have put ten Pine versions of Mittan puzzle, on the eBay auction. A half of the sales of the puzzle will be donated to the AWLQ (Animal Welfare League Queensland) to save stray and surrendered pets, especially our fluffy friends.

Juno, Mittan and I hope you will enjoy the puzzle!

Saturday, April 23, 2022

Bubble Universe

The puzzle, Bubble Universe, has started selling today. This is a puzzle to pack all the pieces into a tray. The tray has two concave sides, one circular and one square.

I have played with both sides, and I would say either side was difficult for me. The pieces seemed to fit into the tray, but they did not. In the end, I wondered if there was an answer. Believe it or not, there is. I do not know how many solutions there are. Maybe, you will find them.

People tend to think that three-dimensional puzzles are more complex than two-dimensional puzzles. Generally speaking, it may be true, but this puzzle is not easy. Do not underestimate this puzzle.


Monday, February 21, 2022

22nd Auction Results, new puzzles etc.

We held an eBay auction, and it successfully ended on 19th February. This time, we had put 2 kinds of puzzles in total 5 puzzles. The sales results are as follows:

The total sales amount was AUD $407.69, so we rounded it up and donated AUD $204.00 to Save The Bilby Fund.
Here is the receipt.

We have started selling our new puzzles, Splitted 12, and Puzzle Turbine on Saturday. Both puzzles are of a very high level, requiring many moves to remove the first piece from the assembled figure. Splitted 12 has unique level 17-22 solution and Puzzle Turbine has unique level 38 solution.

Recently I have heard the sad news that Koalas are listed as an endangered species on the Australian east coast. I wanted to help them and sowed several Eucalyptus seeds last month. Unfortunately, it seemed like I did something wrong, only one could germinate. This is a Eucalyptus tereticornis, commonly known as Blue Gum, one of Koala's favorite trees. Yes, the same as us, Koalas have their favorite tastes.

We know there is a type of puzzle that is the favorite of most puzzle lovers. We are producing new sequential discovery puzzles with great care now. It will still take some time to complete. So, please wait until we release our newsletter.


Monday, February 14, 2022

IPP Competition Results, PuzzleAuction, etc.

The Nob Yoshigahara Puzzle Design Competition held by the International Puzzle Party annually announced the results at 1:00 a.m. Brisbane time today. Honorably, our puzzle, "Sequential Discovery Cubed Box," won a double award, the Puzzlers' Award and the Jury Grand Prize.

We are privileged to receive the awards and most grateful to the puzzle lovers for giving us a chance. Thank you so much.

We will continue to do our best to produce puzzles that make people feel fun and give an essence of the Aha moment.

I was going to write about the auction this time that is going on at eBay now. So, here goes the main part.

Pluredro eBay Auction

There are two kinds of puzzles for a total of five puzzles. As usual, we will donate half of the total sales amount to Save The Bilby Fund. Probably, the Bilby is not as well known as the Kangaroo and Koala. They are also marsupial. Foxes and feral cats that initially didn't habitat in Australia prey on them, and they are close to extinction. We hope that this donation will help to protect them.

We will release the two new puzzles after finishing the auction. If you would like to get the product version, please wait till 19th February.

We know there are lots of people who look forward to the next SD puzzle. We have been working hard to produce the SD puzzle, but it still takes significant time to complete. Sometimes we are asked when it will be complete, but we are unsure. We cannot say when it will become available until the very last moment of production.

Please look forward to it.


Saturday, January 8, 2022

EPP 2021

We have received a good news this morning. Our Sequential Discovery Cubed Box was selected as the most coveted puzzle of the year 2021.

World renowned mechanical puzzle collector and designer Peter Hajek has been organizing the End-of-the-year Puzzle Party, and collecting votes from enthusiastic puzzle collectors to chose the most coveted puzzle of the year.

Our product Slammed Car won the top vote in 2019, SDBB Master in 2020, and Sequential Discovery Cubed Box in 2021. It is a great honor to receive such worldwide support, and we will continue our efforts to create puzzles that will bring fun and joy to puzzle lovers.

We would like to say thank you to Peter who gladly agreed to post about EPP and also use the cover images.

Here is a brief introduction to each of the three puzzles.

Slammed Car (Top vote in 2019)

The puzzle also won the Jury Grand Prize at the 2019 Puzzle Design CompetitionOne of our new toys played an important role in the production of this puzzle.

SDBB Master (Top vote in 2020)

Juno's idea of a six piece burr with six compartments has come to fruition. The puzzle hold a kind of small charm, it has the shape of infinity, in the last compartment.

Sequential Discovery Cubed Box (Top vote in 2021)

We didn't think that the puzzle attract so much interest compared to the other two, so it was unexpected, happy surprise to us knowing many people liked it.

As you will notice, all the three are categorized as sequential discovery puzzles. We are working on the next sequential discovery puzzle, so let's see what the results will be in 2022.