Castle K (ケー城)
On returning from a recent trip to London, my wife bought me a pretty cool お土産 (souvenir) from MUJI.
A Japane castle press-out 3D puzzle/model. Currently unavailable in the EU store but for sale (though out of stock) via the German store.
The last picture (which is the background of the first three) is of a hanging decoration that my wife made for me when we were dating back in Japan.