Secret BL Fairy Tale

This is the story of a merman who falls in love with a human. One day, the prince of the Merpeople suddenly falls in love with a human. He tells a witch that he'll do anything to become human, but in exchange he loses not his voice, but...!? The prince goes to meet the man he loves, but what awaits him is a hell of an unimaginable group pinning him down... It turns out the man the merman loves is a hardcore Yakuza member. Confinement, torture, and torment... Even then, he keeps trying to confess his feelings...