Haruka Hani is a silly, ditzy second-year Hinomori Academy junior high school student who longs to be a princess. When mysterious 'sin-beasts' attack the city, legendary war princesses called Heart Princesses protect it. Haruka and her friend go to scout out a location for the musical when suddenly the Zaiju Aprestia appears in front of them. "Benevolence is the maiden's way! The pink peony of love, Pink Princess!"
