EF-ON Inc. operates as an energy service company in Japan. The company is involved in the energy saving support service business, which includes the improvement of boiler and hot water supply equipment, compressors, refrigerators, air conditioning equipment, lighting equipment, and other equipment, as well as biomass power generation and electricity retail businesses. It also operates and manages forests. The company was formerly known as The First Energy Service Company Limited and changed its name to EF-ON Inc. in October 2016. The company was incorporated in 1997 and is headquartered in Tokyo, Japan.