Cheerful 12-year-old Mayu Kousaka is excited for her first day of middle school until she learns she must sit next to Shinya Amamiya in class. Haunted by his rejection of her feelings for him, she spends that night binging soda at her mother's cafe. Despite her efforts to move on, she sheds a tear that falls into her cup, turning the soda into a seven-colored drink. After chugging the drink, Mayu suddenly encounters a self-proclaimed "drink fairy" named Pucho, who rages at her for consuming what was meant for Pucho herself. Because of Pucho's drink, Mayu now transforms whenever she drinks something—which often leads to disastrous effects! Both Mayu and Pucho remain endlessly distressed until Pucho notices that Mayu may still harbor feelings for Shinya. To make Pucho's seven-colored pixie pop, a human tear must be mixed with seven-colored drops obtained from feelings of love. The two girls take this as an opportunity for Mayu to try again and win over Shinya; but with Shinya being difficult and Mayu's unpredictable transformations, their quest will not be easy.