Like his swimming champion father, Won-il (Seo In-guk) was once a promising swimmer. But when his father dies during a swimming competition (where he was doing his specialty called "no breathing"), followed soon after by his mother's death, Won-il quits swimming for good. Instead, he lives life hopelessly and recklessly, like there is no tomorrow. With Won-il in danger of being expelled from school, his father's longtime friend Jae-suk (Park Chul-min) drags him to a physical education-focused high school, hoping that he'll start swimming again. There he meets his long-ago rival, Woo-sang (Lee Jong-suk) who in the past had always been overshadowed by Won-il. With Won-il's absence from the sport, Woo-sang is now in first place and is a national swimming star. But he gets disqualified from the national tryouts after getting into trouble, so he has to start from ground zero and ends up at the same phys-ed school as Won-il. Woo-sang is Won-il's complete opposite in personality, and all he cares about is winning so he finds Won-il's return to the sport unwelcome. Then there is Jae-suk's daughter, Jung-eun (Kwon Yuri) who captures both Won-il and Woo-sang's hearts and further reignites the rivalry between them. The two very different young men begin training for an upcoming swimming competition, battling for love and friendship as they undergo the rite of passage of growing up.Seo In-guk as Jo Won-il
Yoo Seung-yong as young Won-il
A swimming prodigy who stopped participating in the sport, and now wants to make a comeback. He is a headstrong, impulsive, and live-for-the-moment kind of guy.
Lee Jong-suk as Jung Woo-sang
Nam Da-reum as young Woo-sang
A national swimmer who is uptight and aloof, and hails from a privileged family.
Kwon Yuri as Jung-eun
Kim Bo-min as young Jung-eun
A girl with a carefree personality who dreams of becoming a musician. She grew up with the boys as children.
Shin Min-chul as Jung-dong
Kim Jae-young as Dae-chan
Park Chul-min as Jae-suk
Park Jung-chul as Coach Jang
Sunwoo Jae-duk as Woo-sang's father
Ah Young as Se-mi
Jeon Bo-mi as Ha-na
Lee Chang-joo as Woo-hyun
Park Hyun-woo as Jo Min-gook
Jung Min-sung as announcer
Park Yong-sik as head of swimming association
Kim Young-sun as Woo-sang's mother
Kim Jung-hak as reporter Han
The film began shooting on May 19, 2013. One of the locations was Davao in the Philippines, where the overseas field training scenes were shot, as well as the movie poster.
On the day of its release on October 30, 2013, No Breathing drew 44,707 admissions and ranked 4th on the Korean box office. The film sold a total of 451,669 tickets during its domestic run, grossing ₩2,991,824,739 (or US$2,781,101).
The film also received a theatrical release in other Asian countries in December 2013, namely Singapore (December 5), Hong Kong (December 12), Taiwan (December 13), and Vietnam (December 28). The film grossed over $22,655 on its opening weekend in Singapore, grossing $38,740 during its two-week run. On its opening weekend in Hong Kong, it grossed $35,728 and a total of $53,729 at the end of its run.
On October 22, 2013, CJ E&M Music released two singles for the film, both sung by Kwon Yuri: "Bling Star" and "반짝반짝 (Twinkle Twinkle)."