Canis Majoris is a short science fiction gay film about affection and adolescence that takes place in the peripheral cities of the Federal District, in Brazil. Icaro is a Brazilian teenager who tries to fill his time to kill boredom on vacation. During the summer vacation, returning from a football match, he meets Joao. Together they witness the appearance of a new star in the sky, which makes the nights on Earth red and hot. Trying to cope with the fact that they are growing, with the tedium and the extra heat this summer, Icaro and Joao begin to spend nights together in the streets of the city and discover that, in addition to the star, something is emerging between them.