Long ago, all humans lived beneath the sea. However, some people preferred the surface and abandoned living underwater permanently. As a consequence, they were stripped of their god-given protection called "Ena" which allowed them to breathe underwater. Over time, the rift between the denizens of the sea and of the surface widened, although contact between the two peoples still existed. Nagi no Asu kara follows the story of Hikari Sakishima and Manaka Mukaido, along with their childhood friends Chisaki Hiradaira and Kaname Isaki, who are forced to leave the sea and attend a school on the surface. There, the group also meets Tsumugu Kihara, a fellow student and fisherman who loves the sea. Hikari and his friends' lives are bound to change as they have to deal with the deep-seated hatred and discrimination between the people of sea and of the surface, the storms in their personal lives, as well as an impending tempest which may spell doom for all who dwell on the surface. Long ago, all humans lived in the ocean. But some who longed for the land abandoned the ocean, casting off the special raiments granted to them by the sea god to adapt them to life under the sea... Though mankind was divided into sea dwellers and land dwellers, each with different ways of thinking, they were all still fellow humans, and they continued to maintain contact as time went on. Sakishima Hikari, Mukaido Manaka, Hiradaira Chisaki, and Isaki Kaname live in an undersea village, while Kihara Tsumugu lives on land. When these middle school second-year land and sea dwellers meet for the first time, their hearts begin to undulate like the tides. The youthful fantasy tale of these young people's lives unfolds in a strange and beautiful world.