Blood valentine consists of three women - Chris, her daughter Rinrada and korjai. They are working for Mr. Ralph, the head of a killer organization. However, Rinrada falls in love with Sun, a senior in her university, prompting Chris to try and get rid of Sun which in turn creates a rift in the mother-daughter relationship. As a result, they fail their mission and Mr. Ralph decided to eliminate the Blood Valentine. Besides, it turns out that Sun is a spy who was using Rinrada to get secret information from Mr. Ralph.