Kati is a nine-year-old girl whose mother is suffering from an incurable illness. She must go through steps of happiness and sorrow, bonding and separation, having her hopes fulfilled and losing something she loves. Nevertheless, Kati has learned through these steps that the sorrow from her losses cannot take away her happiness she has received from her mother's love and bonding. This experience allows the little girl to grow up with confidence and courage to live on. She knows who loves her, and who her love ones are.
Unfortunately the movie Happiness of Kati is not yet available on HBO Max.
| Directing | Genwaii Thongdenok | Director |
| Writing | Jane Vejjajiva | Screenplay |
| Writing | Jane Vejjajiva | Novel |
| Production | Jatusom Techaratanaprasert | Producer |
| Sound | Nop Ponchamni | Music |
| Editing | Patamanadda Yukol | Editor |
| Art | Akekarat Homlaor | Art Direction |
| Art | Thamrongrat Wanitsombat | Art Direction |
| Camera | Tanon Sattarujawong | Director of Photography |
