(from back cover) "Pirates are the lowest~~!" Rose, a young girl who stubbornly believed herself to be such type of high-class princess. The one who came to “kidnap” that slightly restless girl some how ended up being a heinous pirate, a crew member of the "Phantom”…!? Blood will race, set sail on a love and romance adventure—Ahoy!!

From CMX:
As a boy, Argentum was a poison tester for a royal family. Later, he developed an immunity to toxic substances and became a master chemist with the ability to cure any illness. Returning after a long absence, he is assigned to be Princess Primula's bodyguard. But any potential relationship will have its limits, as Argentum's very touch has itself become poisonous.