Sinner Jo and border guard Akira make an unlikely team—but now their shared suspicion of Lord Harujion’s Merfolk Island plan has brought them together for a daring mission! Sneaking into Lord Harujion’s residence, they will risk it all to discover the truth of his wicked plot… Ryuu, who let herself become a pawn in the lord’s schemes; Jo, who leads the rebellion against him; and Yuki, the human who is tossed in the turbulent waters between them…Where will they all land when this tsunami of a story crashes to its conclusion?!