Kanako Miyamae transfers to Ame no Kisaki Catholic school in pursuit of true love, inspired by how her parents fell in love there. But there is one difference: because males cause Kanako to break out in hives, she has gone to the all-girls school to find a companion of the same sex. Kanako feels she has found that special someone when she meets the lovely Mariya Shidou; however, there is more to Mariya than meets the eye—it turns out that Kanako's first love is actually a cross-dressing guy. Mariya threatens to expose Kanako's immoral intents unless she conceals his true gender, and to make matters worse, he changes her original roommate so that he can now keep a close check on her.