アビスアジュールの罪人 (Series) favorite_border

[DeepL Translation - needs review] Introduction to Volume 1: The ocean covers about 70 percent of the earth's surface. There exists a world that humans have not yet discovered. A country at the bottom of the sea, thousands of meters below the surface. Joe, a mermaid, lives there peacefully. One day, however, her best friend Ryu is imprisoned for breaking the law. What she broke was the rule that humans must not know of her existence. Why?　And who is the other human?　Jo's love and adventure t...