Heart Rule.

Nabao is the daughter of "Khun Phop", the owner of a famous business. Because Khun Phop's business now has competitors who want to harm him, Khun Phop, who is worried about Nabdao, fears danger, sends a skilled female bodyguard, "Chris", to take care of her. When the two of them are together, many things happen, including their feelings that start to form. But the love between the young lady and the bodyguard is not that easy when a neighbor, "Nicha", comes in to mess with their relationship.