Kensuke Goto, also known as Dr. Koto, manages a small clinic on Koshiki island. On this southern remote island lives Takashi, Kyo, Miyuki, and Kou, 5th graders brimming with curiosity that attend Koshiki Elementary School. Koto watches over them, but many unforeseen incidents occur... A touching story that depicts children growing up through many experiences on the island.