Watashi no Kaseifu Nagisa-san Aihara Mei is a single woman. She works hard as a medical representative at a pharmaceutical company. Unlike her performance at work, she is not proficient at all doing housework. On the night of her 28th birthday, a strange man appears at her messy home. The strange man is Shigino Nagisa, who is an excellent housekeeper. Mei doesn't want to hire him, but she ends up hiring him as her housekeeper. Meanwhile, Tadokoro Yuta appears in front of Mei. Yuta Tadokoro works as a medical representative for a rival pharmaceutical company.