Four men and women working at the same bank get entangled in a complicated romance as they discover how far they're willing to go for love.

A mix-up at the bank forces Ha Sang-su and Ahn Su-yeong to go on a trip together. When they return, he musters up the courage to ask her a question.

Sang-su is left reeling after his tense conversation with Su-yeong. Meanwhile, a new face joins the bank and quickly becomes friendly with Sang-su.

Jeong Jong-hyeon attempts to get closer to Su-yeong, who is grappling with her past. Park Mi-gyeong and Sang-su team up on a work project.

Mi-gyeong reveals her true feelings to Su-yeong while continuing to maintain their friendship. Su-yeong later receives disappointing news at work.

Su-yeong stands up for herself at work — risking blowback. After being embarrassed in front of Sang-su, Mi-gyeong shares her vulnerabilities...

Sang-su and Su-yeong get the chance to open up about their feelings. Mi-gyeong and Sang-su's mothers form an unlikely friendship.

Su-yeong tries to get answers out of Jong-hyeon after his sudden change of heart. Sang-su and Mi-gyeong go public with their relationship.

Jong-hyeon and Su-yeong attempt to adjust to their new — and awkward — living situation. Mi-gyeong's mother tries to track down her...

Mi-gyeong begins to suspect Sang-su's true feelings about Su-yeong. Meanwhile, Su-yeong struggles to manage Jong-hyeon's growing insecurities.

Amid increasing suspicions about Sang-su, Mi-gyeong's anxiety starts to get the better of her. Su-yeong witnesses a scary accident involving her...

After their momentous night at the ice rink, Sang-su and Su-yeong navigate their complex road ahead. Mi-gyeong avoids Sang-su's every attempt to talk.

Mi-gyeong does everything in her power to deny the reality of Sang-su's decision. Confronted with conflicting emotions, Su-yeong reaches a crossroads.

Jong-hyun causes a scene at work after confronting Soo-young about her shocking act. Sang-soo attempts to make sense of Soo-young's behavior.

Steadfast in his feelings, Sang-su tends to Su-yeong during her time of need. After delaying the inevitable, Mi-gyeong makes a final decision.

Sang-su searches for answers after Su-yeong's sudden disappearance. Su-yeong learns the truth about her parents — and realizes her own...

Having moved on to different places in life, the KCU colleagues reunite at a wedding. Sang-su runs into Su-yeong in Seoul after much time apart.