For Yumi Someya, Tokyo is an untapped oil field, full of potential to generate electricity.

The precious fuel, however, doesn't exist underground. It's a resource sitting in the kitchens of millions of Japanese homes — cooking oil.

Someya's ultimate goal is to collect every last drop of used cooking oil, turn it into fuel and distribute the electricity generated from it to the households and businesses that provided it in the first place — a perfect cycle of energy.