Hitogatari

An 82-year-old woman named Ito is told she has only six months left to live. One day, a girl named Hikari—who claims to be an alien—comes to visit her. Hikari asks, “If we switch bodies, would you let me die in your place?” But Ito has already accepted her own death. Then a young man named Fūta, who says he is Ito’s friend, appears… An offbeat slice-of-life tale by striking new author Natsuki Hasegawa. (Source: Comiplex, translated)