Mermaid Boys Vol. 3 (manga)

Love gets messy for Prince Naru when his bubbly fiancée Moana suddenly appears...with legs?! Mermaid or human, it's not the first time a girl's chased after the hot merprince, but there's a bigger problem-they must form a bond or she'll turn into foam! Naturally he's only got eyes for Nami, but he can't just leave Moana to her fate...not when he's the one who led her on in the past. Meanwhile, after learning of Naru's feelings, Moana realizes it'll take more than a confession to get his attention, and approaches a familiar figure for help...who is Arashi?!