Miku(submerged)

Set in a dystopian future where global warming has flooded the world. Siblings Miku and her younger brother Taku drift in to a city partially submerged within ocean water with only the tallest buildings protruding from the sea.

The two have fled home from their father following his descent in to alcoholism since the unfortunate death of their mother and his violent actions towards them that have resulted in Taku becoming seriously injured.

Taking refuge within the top of a clock tower, Miku begins to explore the city in her fishing boat equipped with a motor, in search of supplies to treat Taku. She scales the buildings, locating relief crates that had been parachuted in during the crisis.

The whole time she is observed by aquatic beings who are revealed to be survivors of the city that have undergone a complete mutation to better thrive in their new environment. Miku also realizes to her shock that she herself is now mutating in a similar way.

Eventually she locates the final crate and Taku makes a recovery. They are then confronted by the mutants who perform some ritual that completely purges Miku of her mutation, making her human again.

The siblings then take their leave and move on from the city.