Season 1 of Sunset at Chaophraya premiered on January 28, 2013.

The story was set during World War II when the Japanese Empire sent troops to Siam (Thailand) as part of their greater plan. Kobori, an idealistic Japanese officer set up a base camp by the Chaophraya River which is in the area of Angsumalin‘s house. He falls for her at first sight. Angsumalin, a proud Thai who despises every kind of threat to her country, sees him as a part of the Japanese Empire that deserves only hatreds. Despite his duty, Kobori wants to believe that his love will be able to find its way into her heart.