ReLIFE (2017)

Arata Kaizaki is 27-years-old and unemployed. He quit his prior job after working for the company for 3 months... Arata Kaizaki decides to take part in a research program. He takes medication that makes him look younger and he is to attend high school for a year. There, he falls in love with female high school student Chizuru Hishiro.