In a College for the Arts of some sort, 5 freshmen students (Prim, Foon, Chompoo, Art, and Puen) met randomly during the ceremony on the first day of class. One day, the freshmen were required to donate blood. They learned then that the 5 of them have the same blood type, O-negative.
Prim was into Interior Design. Art was into Photography.
Prim was poor while Foon was rich. Art was not so poor while Puen was rich. Chompoo, in the middle.
Both boys like Prim. Foon likes Puen. Prim also likes Puen but stepped back for Foon, who took her under her wings when Prims mother died. Puen agreed to date Foon to make Prim happy. This saddened Art. He then decided to move to the States to pursue his love for photography.
Foon carried Puens child. Prim was heartbroken and planned to go to the States with Arts help. Foon realized that Puen loves Prim; she had an abortion. On Prims way to the airport, she heard Puen asking for blood donation on the taxis radio. She donated blood without Foon and Puen knowing. Years later, Foon and Puen got engaged. Puen became an art teacher in the university that they graduated. Because of regret and also as a way of asking for forgiveness from Prim, Foon made Prims art gallery dream come true.
During the gallerys opening, Foon received a large photo of Prim and Art in the States, happy together. The movie ended with the The End part of a novel, written by Chompoo.
