Relife (2018)

Kaizaki Arata (27 years old) quit the job he landed after graduating, after only three months. His life hasn't improved since then. Now, his parents are threatening to stop sending him money and want him to return home. He has neither friends nor a girlfriend with whom to share his problems... and as he hits rock bottom, a strange man named Yoake Ryou appears. Yoake invites Kaizaki to join a social rehabilitation program for NEETs called ReLIFE. This program uses a mysterious drug to make him look younger and sends him back to high school for a year...