The cool, beautiful Hikaru Tsuki shows up at Tozai Academy’s elementary school as a new teacher one day. But her true identity is that of a Peacekeeper—and princess!—from the planet Alpha, dispatched to Earth by the Andromeda Branch of the Space Alliance. She secretly investigates the earthlings while living among them under her assumed identity. Aside from her research, she uses the mystical powers of her Moonlight Ring to help the people around her with their problems. With her guidance, even sworn enemies turn into friends—but her eagerness to help sometimes leads to even more trouble! Joining her in her journey are an ensemble of zany, outlandish characters, including her assistant Baru, and the many monsters and oddball villains who regularly show up to wreak havoc!