The Amaterasu Railway in Miyazaki Prefecture, Japan, is a popular local train that takes passengers on a gorgeous 30-minute journey through the spectacular scenery of Takachiho. The quirky train is known for its open roof, its journey over Japan’s highest train bridge, and train conductors who blow bubbles along the way. But now they’re known for something else: leaving passengers feeling hungry. The Amaterasu Railway previously ran on diesel fuel and because of the open roof, passengers would get whiffs of exhaust fumes. However, the railway recently announced that they had switched to running entirely on biodiesel made from leftover tonkotsu ramen broth. Now, instead of that toxic burnt smell, riders report smelling aromas of fried rice. The initiative is a partnership with Nishida Logistics, a trucking company that figured out a way to convert the thick, fatty, pork-based broth into biodiesel fuel. Several of the company’s trucks, as well as the railway, now run on biodiesel fuel.