Lukia is shocked when Kurosuna-kun boldly declares that Lukia is his girlfriend-straight to her fiancé Nam's face! The bemused merman prince isn't one to back away from a challenge, and the boys are soon going head to head in a swimming race for her affections. But when Laurent's minions strike mid-race, the group find themselves quickly getting overwhelmed. Seeing Lukia in trouble, something latent stirs inside Kurosuna-kun...something that might be more than he, or Lukia, can handle...