Guang is a story about two brothers. The elder brother, Wen Guang is autistic. Wen Guang is often misunderstood. Above all, he suffers from attention deficiency disorder, struggles with social interaction, and has difficulty performing day to day obligations. He also has a secret passion. To make ends meet, Wen Guang is coerced by his younger brother into looking for a job to share his burden on meeting their monthly expenses. Throughout the film, we see Wen Guang searching for a job, his daily routines and his secret passion as he searches for the final glass that will bring him a simple, pure, hard earned, fleeting moment of joy.