Shônen no Tama is an educational literary storybook for children preceding Iwaya Sazanami's Koganemaru (1891). Miwa was a teacher and this is his only work. It is a prize winning children's book in a contest held by Japanese Education Board in 1889. It consists of five volumes: one volume carries the judges' examining papers, and volumes numbered one to four carry the story.

  Miwa's story is in line with the conditions of the contest in that the story should be about a person who studied hard and achieved social success. It was actually read to children to confirm their comprehension, and was corrected so that it would be easy for them to read. Such consideration for children was notable in those days. Although didacticism is inevitable, its plot is unpredictable and interesting. It may well be regarded as the beginning of children's literature in Japan.

  The protagonist is a boy named Kunikichi. His pet dog is killed by Torakichi, the son of a wealthy family. Kunikichi buries the dog and plants a cherry tree. The tree bears fruit so well that Torakichi also kills his own dog and plants a cherry tree. The confrontation between good and evil is depicted in such an allegorical story. Kunikichi is assisted by the principal of an elementary school and continues to study after graduation while working. He has a chance to go to the United States where he enters an electric light company. After returning to Japan, he establishes an electric light company and is successful. He helps Torakichi who has ruined himself. The story tells us that studying hard will lead to social success.

  Presumably Shônen no Tama gained some popularity since there was a reprint. It seems to have been received by children through teachers.