Tsubame Group, whose core company is Tsubame Holdings, has increased sales by diversifying its business. Based in Okayama Prefecture, the company is focusing on natural energy in order to continue to grow its operations. Elis, a clean energy company specializing in micro hydropower technology, is a focal point of Tsubame Holdings' efforts. Hydroelectric power generation is both more efficient than solar power generation and emits less carbon dioxide during production.