Off-topic, but it should appeal to anyone here who enjoys working out a sequence of moves: the Japanese puzzle box, or himitsu-bako (秘密箱, "secret box"). It is a wooden box with no lock, no key and no nails that only opens when you slide its panels in the right order.
How it works
The traditional Hakone box is an outer box around an inner box. Some side panels slide up and down, others slide left and right, and small pegs inside travel along stair-like grooves. Each small move frees the next panel, so "opening" is a fixed sequence, and the listing tells you its length: 4寸7回 means a 4-sun box (about 12 cm) that opens in 7 moves. Entry boxes take 2 to 4 moves, the usual souvenir range is 7 to 27, and the long boxes sell at 54 or 72 moves. Boxes marked "+1" have one more secret: a hidden compartment under the lid after the last move.
A shogi-player observation: a long box is not necessarily a hard one. Hakone Maruyama describes its 72-step box as "not difficult once you get the knack", because most of those steps repeat the same few motions. Short boxes and the newer karakuri boxes (from the Karakuri Creation Group, which open by pushing, turning or hidden magnets instead of sliding) are where the real "reading" happens.
A little history
Hakone sources credit Ryugoro Okawa, a joinery craftsman in Hakone-Yumoto, with the box in its present form (dates given range from the late Edo period to about 1894). The surface is Hakone yosegi, a marquetry of naturally coloured woods with no paint, which also hides the seams of the sliding panels. On October 22, 2026 Japan's Ministry of Economy, Trade and Industry designated "Hakone-Odawara karakuri craft" as a national Traditional Craft, so these are getting more attention this year.
Prices in Japan (one Hakone maker's Rakuten listings, checked November 1, 2026, tax included)
- 2-step mame coin bank, 61 mm cube: ¥2,650
- 4-step, 4 sun: ¥7,400
- 10-step, 4 sun: ¥8,800
- 21-step, 5 sun: ¥15,300
- 54+1 steps, 6 sun: ¥41,000
- 72+1 steps, 7 sun: ¥73,000
Search terms that work on Japanese shops: 秘密箱 (secret box), からくり箱 (karakuri box), 寄木細工 秘密箱 (yosegi secret box), 豆秘密箱 (mini box). Check the millimetre dimensions rather than the sun size in the title, since "4 sun" is a traditional name, not an exact measurement.
Disclosure: we're the OneMall team, a Japan proxy/forwarding service, so weigh this accordingly. Our fees are ¥300 per item on most marketplaces and from ¥200 per item on Yahoo Auctions and LinkBuy; shipping is charged on the greater of actual and volumetric weight. For US buyers the $800 de minimis exemption no longer applies (since August 29, 2025), so duties and fees apply at any value.
Full guide with the sun-to-inch size table, the difficulty chart, how to open and close a box, yosegi patterns and where to buy in Hakone and Tokyo:
blog.onemall.jp/2026/11/01/japanese-puzzle-box-himitsu-bako/?ch=blog_puzzlebox_exter
Current Japanese listings for 秘密箱 (prices in yen):
www.onemall.jp/search?q=%E7%A7%98%E5%AF%86%E7%AE%B1&ch=blog_puzzlebox_exter
Does anyone here own one? Curious how the move counts feel in practice, and whether a 7-step box is actually harder to find than a 27-step one.
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