One day, Hina is told by her family that nobody must know her real identity or she\'ll will lose her title as guardian hearts in her home planet. They send her to earth in order to preserve peace from evil monster.When she arrived on earth by teleportation, a young boy named Kazuya discovers her metamorphing ability. Hina asked Kazuya to stay in his home by fearing to return in her home planet in disgrace. Kazuya\'s mom accept and now Hina live in their house. Later, Kurusu, Tracy and Maya, also guardians hearts in their respective planet, are told to find a husband in the planet earth, however, all three of them have their eye on Kazuya during separate encounter with him and now they all live in the same roof. Hina, Kurusu, Tracy and Maya wants Kazuya for themself and they will do anything to make him their husband. Who will Kazuya choose at the end ??? Can the guardians hearts save earth from total annihilation ???? Will the 4 girls get along in Kazuya\'s house before mayhem breaks loose ???