Seung-jin, who is preparing for an audition to pursue his ambition of becoming a singer, moves into a new studio apartment. On the first night, as he just started to settle in, he hears a woman wailing from next door. With all the noise she makes owing to her badly soundproofed room, La-ni has driven away several neighbors. Seung-jin isn't one to back down easily. Their argument intensifies to the point that they have discovered everything about one other's life through their noises save for their names and faces.
Nothing is more frightening, as the narrator points out, than a ‘time-rich nosy person’. Exhibit A is Ahn Geo-ul, who commits herself to social justice causes with terrifying tenacity. After temporarily renting a unit in the Baek-sae Apartment building, she discovers that a loud, hard to locate banging noise occurs from 4am every night, making the residents’ lives an insomniac hell – and so she determines to engage in her own disruption and to find the culprit of this acoustic assault, simultaneously eliminating her eccentric neighbours as suspects, and recruiting them to her cause.
Ji-hoon comes alive only when he sees Ye-eun at college. After a long time, he desires to see her once more. Unfortunately, she has lost her vivacity after marrying her abusive husband, Hyung-oh. Ji-hoon hides under both their noses to rescue her from her suffering.
After trying to cover up a car accident that left a man dead, a crooked homicide detective is stalked by a mysterious man claiming to have witnessed the event.
Kang Chan transfers to Myungsung High School in Busan from Seoul. Tough students at his new school hear the rumor that Kang Chan fought against 17 other students in Seoul. New student Seo Jae-Woo also transfers to Myungsung High School. He came from the same high school as Kang Chan.
Duk-jae is being overlooked at his marketing job and sublimates his unhappiness by getting drunk after work. His boss tells him he’ll be fired if he doesn’t land a contract renewal for Club Hawaii, an establishment where men come to cross-dress in a safe and fun environment. The club owner is willing to renew the contract but only on one condition: that Duk-jae participates to get into the mindset of the membership.
Two brothers fell in love with one woman, Hyun-jae. But she chose Chung-seo. And Jang-seo has been living bitter days ever since the betrayal of his younger brother and his lover. After 17 years passed, Jang-seo gets a call from her. He does not know why she’s coming back, but his heart is beating again.
Han Oh-ki is a weakling. One day, he is working out to become a real man, when multi-sportswoman Chae-in saves him from cramps at the swimming pool. He falls in love with her at first sight and tells her how he feels when they get close. However, he's nothing but a helpless younger brother to her and gets rejected. Oh-ki is mad and challenges her to a sports race and if he wins, she has to acknowledge him as a man...