Seo-eun, returning home for her mother’s 60th birthday, finds herself caught between her parents' conflicting plans while facing pressure about her own marital status.
Seo-eun strives to act more mature, but her feelings become complicated when she encounters Jogging Man, a man who stirs up both admiration and jealousy in her.
As she approaches thirty, Seo-eun briefly experiences hope with unexpected good fortune, only to face a sudden cascade of misfortunes that turn her life upside down.