“Intense, fast, and as long as it doesn’t interfere with my studies—right?” Haneul, who enrolled in a cram school to get into medical school, relieves her stress by kissing Mireu, a guy she met there. When she’s kissing him, she can forget absolutely everything. “Use me whenever you want.” Whenever she’s overwhelmed, Haneul turns to Mireu for comfort, but she has no intention of dating him. He’s a poor swimmer juggling training and a part-time admin job at the academy, while she plans to enter med school and “live a successful life.” At twenty, still clueless about life, their risky, unstable relationship continues. And just as promised, Mireu always goes to her whenever she calls. But then— “Let’s break up. You and I don’t suit each other.” After the college entrance exam, Haneul coldly dumps Mireu. Seven years later. Mireu returns in glory—an Olympic gold medalist. And Haneul appears before him again: holding an agency contract in her hand… looking utterly worn out.