you can't put a futon on a grave; it's too late to show filial piety after your parents are dead
Proverb meaning that once someone has died, you can no longer do anything for them; used to encourage caring for parents while they are still alive.
Be good to your parents while they are well. As they say, you can't put a futon on a grave.
A similar proverb meaning 'when you want to be filial, your parents are gone'; more directly about the regret of lost opportunity.
A general proverb meaning 'repentance never comes first'; broader than filial piety.
A traditional Japanese proverb; the exact origin is uncertain, but it uses the image of trying to keep a deceased parent warm with a futon to illustrate the futility of posthumous care.