Moon in the East, Sun in the West: Operation Sanctuary

Naoki Kuzumi, a high school junior, has been living with his aunt, uncle, and cousin Matsuri since his parents' tragic accident five years ago. His life seems ordinary, except for the fact that his memories of childhood are hazy. However, his mundane existence is disrupted by the sudden arrival of a redheaded girl named Mikoto, who literally falls from the sky and claims Naoki as her younger brother. As it turns out, Naoki's time period serves as a temporal sanctuary for individuals from the future who are afflicted with an incurable disease. Mikoto has traveled back in time in search of her younger brother Yuusuke, who was sent to Naoki's era. With Mikoto's arrival, Naoki's life becomes intertwined with the fate of those from the future, leading to a complex and extraordinary series of events.