A man named Argentum was a poison tester as a boy for a royal family. Later on, he developed an immunity to toxic substances and became a master chemist with the ability to cure any illness. When returning after a long absence, he became Princess Primula's bodyguard. But any potential relationship will have its limits as Argentum's very touch has itself became poisonous. 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.