Nippon Yusen Kabushiki Kaisha (hereinafter, NYK) and its affiliate Sanyo Kaiji Kabushiki Kaisha (hereinafter, Sanyo Kaiji) have started a continuous three-month test navigation using biodiesel (hereinafter biofuel) supplied by Toyotsu Energy Corporation in tugboats operated by Sanyo Kaiji. The biofuel will be supplied via ship-to-ship using a bunkering ship to supply fuel to the tug, .