The original purpose of this Japanese ‘box of tricks’ – known everywhere as ‘Himitsu Bako’ and traditionally made in the heavily wooded area around Hakone – was to protect personal papers or articles from unauthorized hands. Today lovers of high-class games of patience all over the world have fallen for the charm and unusual complexity of these exceptionally pretty objects. The exercise we’ve chosen is tough enough to solve – you need 10 separate part relocations or ‘movements’ (there are some boxes of tricks that need 100 movements to open them up!). Plus it’s been finished in classic ‘Yosegi-Zaiku’ style, with woods of different colours and textures that are glued and cut again and again until the block has got exactly the right pattern so that the strips that make up the box of tricks can be cut off it.

In a corpore sano is, as everyone knows, ideally a mens sana; that the healthy mind with appropriate physical exercise of its own, however, is no more than a vain hope of the endurance runners. The purpose to keep this playfully in motion, serves this classic of its genre.