"Nights Blooming Flowers" tells an emotional story about Cho Yeo Hwa, a woman who has been widowed for 15 years. She is the lady of the most prestigious noble family in the region. During the day, Yeo Hwa lives a peaceful life, keeping herself hidden behind the castle walls with grace and dignity. She is known as an elegant and refined lady, never interacting with the outside world.

However, as darkness falls, Cho Yeo Hwa transforms into a different woman with a mission to aid those in need. Taking advantage of the night, she sneaks out of the castle to provide assistance and warmth to the unfortunate souls. During this jouey, she encounters Soo Ho, a guard within the city, possessing a charming appearance and exceptional skills. Soo Ho is not only a sturdy protector but also a reliable companion, always ready to stand by Yeo Hwa';;;s side whenever she needs help.