Suga Kimio finds himself hiding in the girls locker room, unable to move or escape the situation as the girls in his school crowd in. Although he originally had no ulterior motives, he found himself panicking as he heard the girls coming in and hid in a locker. Komine Nozomi, one of the shy girls in his class finds him, but surprisingly covers for him. Perplexed but glad, Kimio goes home. Later that night, he gets a text from Nozomi who happens to live across the way on the same floor of the complex they both live in. She blackmails him into agreeing to show each other's bodies when she texts him. Kimio has to abide by Nozomi's insane demands or risk ruining his school life so they both start their little peep show through each other's windows... (Source: MangaHelpers)

Gorou Honda, a little boy obsessed with baseball, has always admired his father, Shigeharu. Wishing to follow in his father's footsteps, Gorou dreams of becoming a professional baseball player. In turn, his son's starry-eyed admiration encourages Shigeharu to keep persevering, despite his late wife's death and his unsatisfying position on the second-string team Blue Ocean. Unfortunately, an elbow injury forces Shigeharu off the team, and he falls into despair. However, after an offhand joke from his childhood friend, Shigeharu reevaluates his choices and decides to keep playing, leaving behind his prime position as pitcher and taking up the bat. Now motivated more than ever, Gorou works hard to carve his way in the Japanese Little League. [Written by MAL Rewrite]

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.

The movie is a compilation of episodes 1-8 of the 2017 television series with new scenes added for the introduction. It covers the period from when Riko descends into the Abyss with her robot companion Reg, reaching the second layer where they meet the White Whistle Ozen who reveals information about Riko's mother. (Source: Wikipedia)