This is the second poetry book by Takuboku Ishikawa and it is published after his death. It includes 194 poems and 2 essays. The title "Kanashiki Gangu" or "sad toys" is named from the last line of his theory of poetry. He shows examples about writing system of poetry. In his theory, he mentions how he writes up a poem, such as writing a tanka in three lines, effective usage of indent, how to punctuate, dash and exclamation mark.