Yuu is as industrious and hardworking as a college student can be, but that means guys tend to find her serious demeanor intimidating. Should she have to change her strong-willed personality to be "number one" in someone's heart? Yang is a puppy-like Chinese exchange student who wanders into Yuu's life after she rescues him from a tricky situation. He asks her to be his bodyguard, and they form a new "professional" relationship. But soon, deeper feelings begin to take root...