Aroma is a puzzle designed and exchanged by Iwahiro for IPP 30 in Japan. It consist of a black plastic cage and 3 pieces that need to be put inside.
Note that the shape of the pieces is pretty unusual.
So only 3 pieces, easy? Well yes and no. Yes because you will soon realize how to do, but no because you cannot see if you're doing the proper alignment of the pieces.
As many Iwahiro's puzzle, co-motion will be used!
My technique was to assemble the pieces outside the cage and see how they can be put (but "expanding" them) inside. The fit is perfect, you need precision to solve it!
You just need to understand who the pieces interact. Needless to say that it's very easy to free the pieces outside of the cage. The real challenge is to put them inside again.
In my opinion this is a nice puzzle because it's not big and can be carried out easily. It's for anybody and due to its material it can be played by even a non puzzler as he won't damage it :-)
And regarding the difficulty I would say medium because I am sure that you won't automatically manage to solve it and each time it will take you a bit of time to do it again.