Suibotsu Haikyo no Piano Droid

Half a century has passed since wars broke out over land due to rising sea levels.
Two shadows walk through the submerged ruins, moving from house to house in order to survive.
In the middle of it, they arrive at the concert facility and open the door to the main hall.
There was a woman with long chestnut hair, her fingers dancing on her keyboard.
A trio of submerged ruins with rich tones and stories.
Here 《Start》

[From Steam]