Shizuka, a genius inventor ( known as walking national treasure ) fell in love with Hajime, the Prime minister's son when she was awarded at the Prime Minister's house. Shizuka still pursuits and tries to invent something to make Hajime fall in love with her. But then when she invented a love potion she accidentally drank it and fell in love with some other guy....of course this made Hajime mad because the reason why Shizuka's experiment is not working at Hajime is because...He's already in-love with her.
