When only 19 years old Yayoi found herself pregnant and alone after the tragic death of her lover. Bravely she decided to bring up the child as an unmarried mother. For five years she has selflessly devoted herself to her son. Now 24, a change of job turns her life completely upside down. She falls deeply in love with a colleague called Toru. Unsure of his reaction, she keeps her son's existence a secret. Yayoi is torn between love for her dearest son and love for Toru.