Yosefiel is a Cherubim who goes by the name Joseph who lives on earth that's trying to live the ordinary life of a Cherubim, as he is solely focused on helping people and assisting them while he himself lives a normal life on earth just as humans do, although he is an angel in disguise. All goes well, until there's a demonic force that presents itself that becomes a threat to mankind, and as Yosefiel runs into many other angels of whom are the Seraphim class that are known as the "Guardian Angels", it is after these happenings that he has to decide if he wants to stay out of it or if he wants to help. For the sake of the people, he chooses to assist the Seraphim in their mission, but everything changes once he encounters a half demoness named Cassandra who was born as a half demon. He soon finds himself falling in love with her, except that he doesn't know if the others are able to trust her, and in the end, it's up to him if he wants to help her or not, but the only problem is that it may just cost him everything...