Yuno and the Siren

The last thing Yuno remembers is being on board the sailing ship the Golden Dawn in a storm. Now he's in a sea cave with someone that has glowing eyes, a bad attitude, and a tail. A fish tail. Who keeps mentioning that he would have rather eaten Yuno than brought him here.So, yeah. A siren. Great.Yuno's been looking for his brother for months without any leads. The siren might have some answers, once they get over the aforementioned attitude problem. They're going to have to work with the siren's brother though, and then the crew of the ship the Black Bull. Only, there isn't a Black Bull any more, and how can their Captain be a Captain if he's afraid of the ocean?