The box office has been seeing the coming of a new storm, as it took just 36 hours for Be Covert, Be Great to sell a milion tickets. According to the Korean Film Council′s Compiled Ticket Computer Network on June 6, Be Covert, Be Great, which premiered on June 5, gathered an audience of 1,011,025, making it the quickest Korean film to reach a million. On the day of its premiere, its opening score amounted to 498,284, destroying the record set by The Thieves for biggest opening-day audience for a Korean film. The number even surpassed that of Iron Man 3, which marked 422,538 moviegoers on its opening day. The speed at which it passed the million mark is also especially surprising considering how Transformers 3, which sold 540,000 tickets on its first day and became the film with the biggest opening day score in Korea, reached a million audience on its third day. Be Covert, Be Great is about three flower boy North Korean spies who stay undercover in South Korea. It is based on a webtoon of the same title, and gathered attention for its flower boy cast featuring Kim Soo Hyun, Park Ki Woong and Lee Hyun Woo.