Japanese box made entirely by hand.
CHALLENGE: find the right steps to open the box
When the Osaru, the monkeys, manage to carry the Kago, or the porter, from Odawara castle to the Hakone checkpoint... only then you will be able to arrive at the solution!
Difficulty: 3/6 HARD*. Average solution time: 20 minutes - 1 week
Dimensions: 12 × 8.4 × 4.8 cm / 4.7 x 3.3 x 1.9 inches
Internal space: 6 × 9.5 × 2.7 cm / 2.3 x 3.7 x 1 inches
Made with cherry and zelkova wood
Made manually on Lake Ashi in Japan, in a village of artisans who have been engaged in wood inlay work for approximately 300 years.

*difficulty level and solution time indicated are subjective; much will depend on the skills of the individual player

Yosegi inlay work
It is said that the yosegi inlay works, typical of Hakone which is on Lake Ashi, were born thanks to the work of Nihei Ishikawa, during the last period of the Edo era (1603-1868).
Hakone's inlay works, enhancing the infinite variations in the natural color of the wood and the traces of its grain, represent one of the most sophisticated woodworking techniques, a manifestation of an art that expresses the perfection of geometric motifs through refined skill manual handed down for generations. Objects such as boxes or drawers are made through a particular filing process using a special plane, and the refined tablets depicting particular motifs are shaped to form trays or bowls.