A dream of falling from the sky...and then birth. Rakka is born from a large cocoon into the Old Home, greeted by a group of females with small wings on their backs and shining halos above their heads. Soon Rakka's own wings grow, a halo is placed on her head and she is told that she must work in the nearby town of Grie. She soon realizes that the town and the entire world they live in are confined behind the Wall, a tall, impenetrable wall that none except the mysterious Toga are allowed to exit.
Tetsuo Takahashi is a teacher working at Shibasaki High School and specializing in the physiological studies of demi-humans. His students include Hikari Takanashi, a vampire and lover of tomato juice; Kyōko Machi, a dullahan; and Yuki Kusakabe, a yuki-onna. The school also employs math teacher Sakie Satō, a succubus.
Asahioka Branch School, a combined elementary and middle school in an isolated village, has only five students total, four girls and one boy. The girls are best friends, and pass the season with traditional activities like harvesting mountain herbs and fishing.
With just five students (none in the same grade ), the four girls of the tiny Asahioka Branch School still enjoy watching cherry blossoms, playing in rivers, digging potato, and building igloos together. The pace is very slow yet enjoyable and heartwarming.