Stranger Things is an American science fiction and horror series written by The Duffer Brothers, premiered on July 15, 2016 on Netflix. The story takes place in the fictional Hawkins City of Indiana, in the 1980s, the first season focuses on investigating the disappearance of a young boy amid supernatural events that occur throughout the city with the disappearance of this boy called Will in the inverted place.

Including the appearance of a girl with sensory psychological abilities who escaped from a Hawkins laboratory helps the missing child's friends in their own search for their friend.
Here are stranger things real life age :
Source 1
Attribution - Sources - licenses