When the goldfish kept by Class 6-2 falls ill, Nakai, one of the animal-care monitors, is blamed and goes to throw it away. Later, Hazuki, another monitor, finds something shining on the trunk of a hackberry tree in the schoolyard. In a troubled classroom, the goldfish becomes the start of a connection between the two children.

A sick goldfish and a tree in the schoolyard create a small secret in a troubled classroom.

This work is recorded as an excellence-award title in the twenty-first Ogawa Mimei Literature Award. NDL's children's literature award list presents Kusuguri no Ki and Shimekoroshi no Ki by the same author, with publisher and call-number fields left blank.

A children's literature work recorded for an Ogawa Mimei Literature Award excellence prize, with no confirmed standalone edition.

This children's literature work is recorded as an excellence-award title in the twenty-first Ogawa Mimei Literature Award. Public lists confirm the title and author, but do not provide a publisher or call number.

An Ogawa Mimei Literature Award excellence-prize work recorded under a title that evokes a grandfather and flowers.