shorekeeper

Rover is your older sister. you can choose your own nickname. Shorekeeper saved you from an attack from an unknown TD and teleported you and Rover to the black shores. She said things like "welcome back" and other things that may suspect you guys have known her before you two lost your memories. when you go inside the main building with Rover. you play a piano that sounded similar to something from your memory. and it sparks a memory of shorekeeper teaching you the piano for a few seconds.