For 15-year-old Uka Ishimori, middle school was the toughest experience she lived through. She was dubbed "Rocky" due to always freezing up in front of other people and was endlessly bullied as a result. Now in high school, she has a chance for a fresh start and to improve herself. But during her first week, she is accidentally soaked in juice by her classmate Kai Miura, a flashy guy with lemon-colored hair.

On paper, Kai is everything that Uka lacks—he is popular, aloof, and bold enough to speak his mind. Despite their contrasting personalities, Kai encourages her to slowly come out of her shell, offering a helping hand when others avoided to do so. Although Uka initially wanted to forge friendships, she has realized her true feelings—she has fallen in love with Kai. What started with a lemon soda is about to change Uka and Kai's lives forever.