As far as environmental measures go, the Japanese Government has hit on one many would be more than happy to live by.
At the restaurant in the hotel for the G20 Foreign Ministers' meeting, brochures on the dining tables contained an order to eat everything on your plate.
"Thank you for finishing everything on your plate! Wishing you great success!"
The brochure explained it was a campaign to reduce leftover food "to help conserve the global environment".
Some of us had a great deal of success indeed at following this order, all in the name of conservation of course.
One other company in Japan is taking this to extremes by providing the ability to even eat the plate the food is served on.
That is a small Japanese confectionery company which offers edible takeaway containers, and is working on an edible coffee cup.
The cups and edible takeaway food trays are aimed at tapping into the global push by Governments, companies and consumers concerned about plastic and waste pollution.
On a per capita basis, Japan is the second highest user of plastic in the world and goes through 30 billion single-use plastic bags in a year. But in a bid to meet the United Nations' Sustainable Development Goals, it is trying to clean itself up.
There is now a proposed plastic bag ban - or at least a fee - and subsidies are on offer for business projects.
The edible ware is being developed by a small family company in Aichi prefecture, which has also developed edible chopsticks and takeaway food plates - flavours include shrimp, sweet potato, onion and corn.
At the small Marushige Seika factory on the outskirts of Nagoya, managing director Katsuhiko Sakakibara said the idea came from the company's business making wafers for ice-cream and packaging shrimp crackers. The development of the product had some subsidies from local government.
"In the food industry, there is an awareness of environmental issues," Sakakibara said.
"There is a global trend against plastic and a growing awareness among the general public, as well as more subsidies for these sorts of projects.
"So there is a new market for edible containers and there are consumers who agree with our way of thinking."
The consumers targeted were those who were green-minded, vegetarians and health conscious. The containers were recently used at a festival, and Sakakibara said they were ideal for sports events too.
The plates and cups are mainly made of wheat and potato starch and the idea was born about eight years ago.
The coffee cups are still a work in progress, not yet ready for the market. An edible spoon is also on the way.
The recipe for the waterproofing of the top and bottom layers is a commercial secret, but is safe to eat, he said.
The biggest test of all is the taste. The company's first edible cutlery invention was chopsticks, which were described as tasting like wood.
The new products fare somewhat better in the flavour department.
The NZ Herald found the coffee cup very edible indeed - slightly sweet and a bit like a wafer biscuit although the thicker parts around the handle were a tad too chewy.
A chew on the shrimp-flavoured food tray saw it too get the thumbs up - like a mildly flavoured prawn cracker.
The trays can hold liquid for more than an hour without it seeping through.
Sakakibara listed the challenges faced in launching the products - the first of which is cost. They cost about 10 times as much as plastic trays.
That was partly because they could not yet be mass produced.
At the moment, the containers are made in moulds by hand. It involves a starch powder being poured into heated moulds, which melts, crackling as it goes.
Any waste is taken to the local pig farm to feed the pigs.
Sakakibara said the company had had inquiries from Australia, but it did not pan out because of the complexity of importing to Australia, including quarantine issues.
He said one solution for countries such as Australia and New Zealand could be to make the products domestically in countries with those issues.
However, such global expansion was some way off.
One day, however, coffee drinkers could have their coffee and eat the cup too.
* Claire Trevett is in Japan as part of a journalists' programme funded and organised by Japan's Ministry of Foreign Affairs.