Santiago is a teenager from Uruguay with astigmatism. When he starts using glasses for the first time, he feels like he is seeing more of what is supposed to, like weird shadows, sometimes almost human shaped that are everywhere, but no one else seems to notice them.

His best friend is Mauricio, they are classmates at high school and walk together there almost every day. When he meets Mauricio's girlfriend Josefina again after starting to use his glasses, he notices that she is also able to see these creatures, and in fact there is one always following her, Noir, a tall humanoid-shaped shadow, with sharp teeth and long strands of paper-like hair.

Him and Josefina didn't get along before that, but they decide to cooperate to discover where these creatures come from. Later they also make Mauricio join their investigation, even if he cannot see them. Because of this Mauricio thinks is just some kind of role-play game.

He can appear kind of apathetic and always looks tired because he doesn't sleep very well, he suffers from insomnia even before using glasses.
Santiago sometimes likes to act more mysterious than what he actually is and Mauricio always calls him out on that. He makes almost no noise when walking and sometimes gives a crooked smile instead of an answer.

He lives with only his mother, who has a compulsion to waking up very early and opening all the curtains of the house the minute the first rays of sunlight come out. His father is disappeared since Santiago is little and he doesn't remember him very well.

Apart from the astigmatism, he has celiac disease, so he doesn't eat things with gluten. His favorite foods are citrus and yoghurt, which he must spend some time reading the ingredients to check it doesn't have thickeners that would be bad for his health, his refrigerator is always full of oranges.