As the last summer day fades, all is illuminated. With gorgeous translucent designs by Mel Kishida, as well as a story that depicts the youth of lifelike girls, based on a theme of human identity and bonding, a new title in the BLUE REFLECTION series is here! Under a piercing blue sky, surrounded by crystal clear water, the sun scorched Ao Hoshizaki's skin. Gazing at the summer scenery, it seemed as if the girl was left behind in a world that she had wandered into. At a school adrift in the distance, there lived three girls who had lost their memories. The only thing they could remember was their names. Ao, shrouded in confusion, begins to lead a strange communal life with the girls as they seek clues about a way to return to their original world. One day, in this world where the school was surrounded by nothing but water, a path that led to new scenery suddenly appeared. At the end of the path was a mysterious location, where familiar things existed inexplicably. In order to grasp the situation, the girls decided to venture forward, but as soon as they took their first steps, they encountered a monster they had never seen before. But just when they thought things had become hopeless, the girls obtain a mysterious power. In a world that seemed to be trapped in summer, young girls have lost their memories. If the girls solve the mystery, what will they obtain?