She's just a girl from school

The main character Isabella is a student in High School, with her best friend Jacob.
One day Isabella noticed a girl in the hallway who was getting ready for class, she always knew she went to that school but she never paid attention to her. Weeks and months passed, but Isa was unable to start talking to her, until one day in sex education, the students had to choose a partner with whom they would do a project for a week. But that day, Jacob was absent, so Isa and the girl from the hallway were left alone and had to be together for the project. And this is how this story begins.