On a summer night filled with shooting stars, a mosquito transforms into a human woman. Given the name 'Bada', she ends up living together with 'Cheong-do', the man who tried to kill her. Everything is a first: eating, dressing up, and liking someone. The fluttering heartbeats, the kisses, and the thrilling sensations felt in a human body are all entirely new. And the partner for all those 'firsts' is Cheong-do. "Cheong-do is my absolute favorite." Bada is honest because it's her first time, and that makes Cheong-do even more cautious. Can he really accept the heart of a girl who doesn't even know what love is? He knows he should draw a line, but the longer they spend together, the prettier Bada looks to him. When she gets close, he's hyper-aware of her; when they touch, he wants to touch more. He finds himself wanting to teach her things he probably shouldn't. Bada, a human novice experiencing love and desire for the first time, and Cheong-do, a man who has to hold back more the more he falls for her.