A small exhibit at London's Design Museum, called Product Fitness 80, shows how they are rethinking their products by using 20% less materials and energy.
Minimalism has always been at the heart of their design philosophy but now, in the aftermath of the Japanese earthquake, they are re-examining excessive consumerism and questioning over-packaging, use of materials and weight of their products.
It is a fascinating process: as they say "it can be frustrating reducing an item to its essentials but with practice it becomes natural and even enjoyable."
So how does it manifest itself in their products. Take toilet paper: why does it have to be so wide? By narrowing the width, resources are saved, it works just the same and packaging costs can be reduced. The same with Q-tips: they can be shorter and still clean your ears.
The Japanese value old things: why should a crack in a bowl make a difference? The gold lacquering method has long been used to repair damaged or broken ceramics.
These socks are made from left-over thread from the weaving of cloth. Muji has collected it and used it to make socks and stuffed animals. Each one is different.
What about credit cards...no subject is too trivial for their focus. There is no reason why they have to be so large. By halving the size, the functionality is the same but they take up less space in your wallet.
Who doesn't have tons of lids taking up space in the kitchen. This one has five different sizes in one, now that's an idea.
This too is genius: a hole at the top of the handle of your umbrella. Put a tag on it with your name and presto: no more lost brollies, picked up by mistake.
And finally, the humble plug. Except this one is made out of regenerated PET bottles, and it cuts CO2 usage by 10% by conserving the energy from appliances on stand-by.
As Muji says "Just as changing our diet or taking up exercise, although sometimes painful at first, helps us become fit and healthy, Muji hopes that as a world society we will chose a sustainable path for the greater benefit of our Mother Earth and all her people."