Toki wo Kakeru Shoujo Episode 1

Shohei one of the visitors from the future gets stuck in the present time and goes undercover in a high school. He manipulates the memories of every person around him into believing he is a fellow classmate, son and friend. Miharu and Gore best friends since childhood also believe they've always been three instead of 2. This way Shohei wants to spend his time in the present peacefully. He enjoys experiencing the way of living 'back then' all the while experimenting on the drug that should bring him back to his time. Things start to get complicated at the end of the episode when Shohei starts falling for Miharu after been rescued by her and gets in the way of Goro who also has a crush on her.