To commit harakiri with a pestle.
More Japanese Proverbs:
One cannot always find a fish under a willow.Japanese
If you run after two hares, you will catch neither.
Japanese
To receive a favor is to sell one's liberty.
Japanese
Unless you enter the tiger's den you cannot take the cubs.
Japanese
Duty is heavy as a mountain but Death is lighter than a feather.
Japanese
One sees the sky through a hollow reed.
Japanese