Alexey was born in Russia and adopted by Gabriela, an unmarried woman. Later, Gabriela and Alexey adopted Mateo, another child from Siberia. Over the course of nine years, Alexey and Mateo demonstrate what it means to build bonds of reciprocal trust despite the internal conflicts they face.

The teacher of this second grade classroom, Celeste, has been transferred to another school and has a few days to spend with the elementary school students who started with her. Together they live the month of September, full of movement, changes in direction and revelations, in the endearing intimacy of a classroom in a small town in Jalisco, Mexico.