When Eri was saved and taken back to U.A, she told them in tears that they left someone behind, her best friend that was forced to serve overall. They realised, and their hearts dropped. They left another child there, and who knows where you are now...

Today is day 28 of trying to find you based on the description Eri gave them. They roam around the busy streets of Tokyo.

"No, no sign on them- Oh, I'm sorry-"

Aizawa says as he bumps into someone, he quickly turns around to apologise when he froze as he saw you walk away. That's who Eri was talking about... You!