Rak Kern Pi Kad Kaen

Thirty years ago, Athip (Dilok Thongwattana) and Kuea were close friends working for an arms dealership. Their friendship shattered when Athip caught Kuea stealing weapons to pay for his wife's childbirth expenses. Athip shot Kuea dead in front of his pregnant wife, Supha, though he allowed her to escape. From that day on, Athip rose to become a powerful boss.
Supha fled to her hometown in Nakhon Sawan to give birth, but she soon died of a broken heart, leaving her son Thai (Patiparn Pataweekarn) to be raised in poverty by his grandmother and aunt. Tragedy struck again when Thai's aunt, Suda, was killed in a car accident. This forced young Thai to shoulder the burden of caring for Yai Sin (Pissamai Wilaisak) and Nong Nu (Bandita Srinuanat), his 7-year-old cousin who suffers from a brain disability.
Thai dreamed of becoming a lion dancer, but after a fire destroyed their home, he moved the family to Bangkok to find work. Through sheer endurance and hard labor, he supported his grandmother and cousin while putting himself through school.
Thai’s life stands in stark contrast to Yittha, or Khun Nu Yin (Suvanant Kongying). Yin is a literature graduate from London who dreams of being a writer, but her father, Athip, pressures her to join the arms trade. Her mother, Nithra (Rungnapha Kitiwat), often acts as a mediator between father and daughter. Yin’s only confidante is her best friend, Bulla, or Aey (Sarinya Suansuwan).
One day, Nithra is mugged, and Thai happens to be there to help. He catches the thief but gets injured and ends up in the hospital. To repay him, Nithra hires Thai as her personal driver. When Athip sees Thai, he is shocked by the young man's striking resemblance to Kuea—the friend he murdered. After investigating and confirming Thai's identity, Athip becomes wary of having Thai near his family.
Thai meets Yin again at a charity auction for children with brain disabilities organized by her. At the event, Trakun (Attapon Anurutthikon), the son of a prominent banker, pursues Yin openly, while Santhan (Pongsakorn Mahapaoraya), a doctor who owns a foundation, also admires her. Trakun’s sister, Tridao (Yupapak Watcharaphai), warns him that Yin is the daughter of an enemy, but he ignores her.
At the flat where Thai lives, he is supported by Krawan (Nadia Nimitwanich), a sharp-tongued but kind noodle vendor, and Bat (Attaporn Teemakorn), an assistant at a dog grooming shop. While Bat has a crush on Krawan, Krawan secretly loves Thai.
When Thai secures a stable job, he takes his friends to Pattaya to celebrate. There, he saves Yin from being harassed by a foreigner, sustaining a head injury in the process. Athip is furious that Thai continues to put Nithra and Yin in his debt. Later, Thai narrowly survives an assassination attempt while protecting the two women. Realizing he can use Thai's loyalty to his advantage, Athip hatches a plan: he officially hires Thai as a bodyguard for Nithra and Yin, while secretly training him in advanced weaponry and silent combat.