Tsuki ha Higashi ni Hi ha Nishi ni: Operation Sanctuary - S01

Naoki Kuzumi is a high school junior whose parents died in an accident five years ago, and he lives with his aunt, uncle, and cousin Matsuri. He has always figured his life was ordinary, except that he cannot remember what happened in his youth. One sunny day, while he is napping on a bench, a redheaded girl named Mikoto literally falls on him from the sky. For some reason, she believes he is her younger brother. Naoki's era is a temporal shelter for people from the future, where many are suffering from an incurable disease. When Mikoto heard that her younger brother Yuusuke had been taken to Naoki's time, she went back in time herself.