Septiembre de 2021. Un grupo de peligrosos delincuentes coreanos tiene que ser trasladado en un buque de carga de Manila a Busán. Los acompañan a bordo el capitán de la policía coreana Suk-woo y otros 22 detectives experimentados, cada uno con al menos 10 años de experiencia investigando crímenes violentos. Pronto, la prisión flotante abandona el puerto y comienza su camino hacia Corea. Los prisioneros están fuertemente custodiados y todo está tranquilo a bordo hasta que los criminales inician un motín.
Joon-il, who was once a national team-level prospect, now just a coach at a local soccer class. He is on the verge of being fired for his old-fashioned mind and lazy coaching, and is about to get divorced. Joon-il is given a mission he can't refuse in exchange for a full-time job.
It was the final round of the amateur futsal tournament of the "Cheolsoo Soccer Team." In a very short period of time, Joon-il had to transform President Kim, Mr. Choi, and Mr. Park who had no previous knowledge of the sport... Oh my futsal!
With the dreams and livelihoods of grown-ups on the stake, "Sunday League" begins!