A comedy manga by Morinaga Ai, of My Heavenly Hockey Club fame. It stars a violent tomboy by the name of Momoi Nanako, and a shy boy by the name of Uehara Akira who has a crush on her. So far, normal enough. When Akira drops by her house to deliver some handouts from school, he gets mixed up in an experiment that Nanako's Mad Scientist grandfather was performing on her. When the smoke clears, they discover that Nanako and Akira have swapped bodies. Of course, they also discover that the machine that did it is trashed, and it's going to be neither cheap nor quick to get it fixed... not that Nanako's grandfather seems to be in any hurry to work on it.