back to the drawing board
01
振り出しに戻る, 最初からやり直し
used when one has to return to the beginning of a process and redo the process after one's effort has failed
idiom
例
The prototype of the product did not work as planned, so we have to go back to the drawing board and come up with a new design.
最初のマーケティング計画が失敗し、また振り出しに戻った。
