Kim Do Jin, Im Tae San, Choi Yoon and Lee Jung Rok are four 40 year old men, who have been friends since they were teenagers.Kim Do Jin is an architect with a scathing tongue have romantic relationship with strict high school teacher Seo Yi Soo. Im Tae San is dating a cold-hearted woman but wonders if there is someone else out there for him. Choi Yoon tries to heal his heart after losing his wife four years ago. Lee Jung Rok marries an older woman for money but may lose his comfortable lifestyle in a divorce. The story of four men in their forties as they go through love, breakup, success and failure.