Ai Morikawa is an exceptional Tokyo employee who is devoted to her work and exhibits unwavering diligence. Despite a grueling and exhaustive evening at the office, she was elated when a attractive young gentleman appeared at her doorstep. Nagisa, her sister's stepson who is sixteen, was entrusted to Ai's care while his parents were preoccupied with their jobs. Despite their contrasting ages and solitary ways of life, Ai and Nagisa must collaborate to create a fresh start.