The main character, Gorō Mutsumi, has no luck at all, not with jobs, nor with his schooling, and especially not with women or girlfriends. That is until the day he meets a fortune teller who informs him that he will have a fateful encounter and adds a spell to his cell phone that allows his guardian angels to appear to him. Gorō does not believe her and walks away as he remembers all of his previous times of bad luck with women.
It is then seen that he meets three girls who are waiting for him as he is bathing. They say they are now his Guardian Angels, sent to Earth from the spirit realm by the Goddess. They are the first three of his twelve beloved pets who had died due to Gorō's poor luck, returning to him on earth. He does not find out they are his pets at first.
Soon after more and more of his former pets return to him as guardian angels, and each desires to be seen as number one in his heart, as his favorite pet. Each also has fears which they must overcome, fears from their past lives, for to overcome them and to learn to live with each other as one big family is the only way they will ever stand a chance of helping Gorō turn his life around and gain some good luck that his life was missing.
These girls however are not the only ones on earth, because of Gorō's own past life, because of what he was in another time and another place, there are strange people out there trying to put a stop to these girls turning his luck around. For their own reasons, these people fear Gorō and desire him out of the way. As the story progresses the girls learn they must protect Gorō not only from his own bad luck but from these other people, without fully understanding either who they are or why they want to harm their beloved master.