The narrative begins with Han Ki-jun breaking his 10-year relationship and impending wedding with Jin Ha-kyung after sleeping with Chae Yoo-jin (who was dating Lee Si-woo). Ki-jun and Yoo-jin marry rapidly, while Ha-kyung and Si-woo connect impulsively after discovering their mutual betrayal and subsequently enter into a secret office romance.
As Ki-jun struggles financially after overpaying for his apartment and Yoo-jin delays registering their marriage, Si-woo's estranged father repeatedly extorts money from Ha-kyung and Si-woo. Seeking space, Si-woo accepts a deployment to Jeju Island's Typhoon Center. During severe storm tracking, an atmospheric balloon explosion injures Si-woo's eye, forcing Ha-kyung to confront her fear of losing him.
To spare Ha-kyung from his toxic family background and differing views on marriage, Si-woo initiates a breakup while office rumors expose their past relationship. In the finale (Episode 16), Si-woo's father is diagnosed with lung cancer, leading to mutual forgiveness. Ki-jun matures as he and Yoo-jin prepare for an unplanned baby. Gathering under the first snowfall, Ha-kyung and Si-woo choose to face life's climate together, resuming their relationship on honest, mature terms.