Destiny has brought Ten and Pao to meet through a story in touring book. Though they haven't seen each other yet, the letters in the book was written and sent to both of them. Until one day, when they meet by chance, the acquaintance they've made through the book begins to blossom and develop into love. They vow not to be apart from one another no matter what would come. There's a twist when Ten doesn't get his birthday present that Pao sends to him, but they still hold on to the vow that one day they'll be together forever.
Unfortunately the movie Happy Birthday is not yet available on HBO Max.
| Directing | Pongpat Wachirabunjong | Director |
| Writing | Kongdej Jaturanrasmee | Writer |
| Writing | Kongdej Jaturanrasmee | Screenplay |
| Camera | Sayombhu Mukdeeprom | Director of Photography |
