After sending his only niece, whom he had raised since his brother and sister-in-law's tragic accident, off to be married, Police Inspector Seo Gun-seok finds himself feeling old, tired, and empty. That is, until his world takes an unexpected turn when an unanticipated visitor arrives. Cho Jun-heon stirs up painful memories. As his niece's childhood friend, Gun-seok had witnessed Jun-heon's growth, even teaching him how to shoot, which eventually led to Jun-heon pursuing competitive shooting. However, Gun-seok's last memory of Jun-heon is rejecting the university student's feelings. But as if nothing had ever happened, Jun-heon reappears six years later: taller, constantly flirting with Gun-seok, and seemingly hiding something…