Wayan Sumerta falls flat on his face in the mud, showering his colleagues. Not that there's any chance of the hefty martial arts expert injuring himself - he is a black belt in the art of landing safely, as well as kick-boxing, dancing and playing Balinese traditional music.
There is just one day to go before the opening of The Green School on its Kul-Kul campus in Sibang Kaja, Badung, in Bali. Wayan and the team, led by Putu Witsen Widjaya, are rehearsing a demonstration for parents the following morning.
There is more to the Mepantigan Arts they are performing than just the sparring and entertainment, though, for its disciplines are based on the three Balinese principles of harmony - man with man, nature and spirit - that go to the heart of the philosophy of what may be the world's first total eco-school.
Widjaya, who in 2003 invented Mepantigan - a blend of the Indonesian Penchak Silat martial art, judo, taekwondo, kick-boxing, Brazilian capoeira and traditional Balinese music and dance - said the arts complemented a curriculum aimed at giving the school's pupils an emotional and spiritual education alongside their academic and intellectual development.
The first batch of 100 pupils come from 16 countries.
The non-profit school, on an 8-hectare site on both sides of the Ayung River, is revolutionary. The open-sided classrooms and furniture are made entirely of bamboo. Classic-looking grass-thatch roofs and bamboo spires complement futuristic sweeping architectural curves that make the buildings look like sculptures.
The compost toilets recycle human waste for the vegetable gardens, a water vortex generates the site's electricity and the pencils are made out of cinnamon bark.