Runway de Waratte starts with the story of Fujito Chiyuki, an aspiring fashion model and daughter of a fledgling Modeling Agency, Mille Neige. Ever since she was little, Chiyuki's dream was to be the star model of her dad's agency and perform at Paris Fashion Week. With great looks and a gifted environment, it seemed like she was on the right track to fulfill her dream, but she soon found herself faced with a seemingly insurmountable wall when her height stopped growing at 158 cm; too short to be a professional model.

Although Chiyuki still kept on believing in herself for years despite everyone telling her it's impossible, Chiyuki's resolve starts to crumble as she enters her last year of high school. This is when she meets Tsumura Ikuto, a lame classmate with a surprising talent for designing clothes, who is also considering giving up his dream due to unfortunate circumstances. Together, they begin the journey of doing the impossible in order to realize their dreams.