Nang Sao 18 Mongkut

Nam, whose name in the boxing industry is Nam Dok Mai, is a hardworking young woman with a variety of jobs. She works as a delivery boy, a boxer, and a bounty hunter.
She is the pillar of the family and supports her parents, Suprap and Pranee.
Mr. Buntawee, the Executive President of Well Fed Sauce, suffers from Alzheimer's Disease and is searching for his grandson, an heir to the family fortune who disappeared twenty years ago and is due to receive 15%
company stock on his twentieth birthday in just a few weeks.
The company lawyer, Mr. Chaichan, got drunk and offered the patrons in a bar a huge sum of money if they help him locate the missing grandson.
Nam's parents, who swindle others for a living, decided to pass off Nam, whom they had stolen from the hospital as a baby, as the missing grandson. To hide her true identity, Nam was required to live and dress as a boy since birth.
Pranee, Nam's foster mother, contacted Mr. Chaichan and convinced him that Nam was the missing grandson in order to receive the award money.
Tana is the eldest grandson of Mr. Buntawee and takes care of him.
He also wants to find the missing heir because he is battling his ambitious Aunt Marisa for control of the company.
Tana wants to combine his stock with that owned by his grandfather and the missing heir so that he can keep the company in the family.
Tana forms a deep bond with Nam, whom he treats as his brother, and invites him into his home and offers him an executive position at the company.
To conceal her true identity, Nam tells Tana that she is a ladyboy.
Tana's ex, Lisa, returns from abroad and wants to reconnect with him but this creates tension between the three of them. Grandpa knew from the start that Nam was not his true heir but decided to play along because he loved
Nam and because he knew that Nam (and her parents) was his only hope of finding his missing grandson. Will Nam and Tana find the true heir?
What will happen to the relationship between Tana, Nam, and Lisa? (Source: drama.fandom)