Japan's maritime industry is witnessing a significant shift towards innovative clean energy solutions led by Mitsui O.S.K. Lines (MOL). MOL has launched Japan's first LNG-fueled ferries, the 'Sunflower Kurenai' and 'Sunflower Murasaki,' as part of the 'ISHIN-II' concept to reduce environmental impact and GHG emissions. The company is also actively developing vessels fueled by ammonia, with basic designs for different ship types granted Approval in Principle (AiP). Moreover, MOL is pioneering the concept of an Ammonia Floating Storage and Regasification Unit (FSRU) to support ammonia as a clean fuel, addressing the increasing demand for ammonia transportation. In addition, MOL is working on the development of 'Liquefied CO2 Carrier' concepts to transport both CO2 and ammonia efficiently. The onboard demonstration of a marine hydrogen fuel engine and the Wind Hunter Project highlight MOL's dedication to exploring zero-emission vessel concepts and utilizing hydrogen as a next-generation fuel in the maritime sector. These initiatives signify a positive step towards a more sustainable and environmentally friendly maritime industry in Japan.