expression
even the hardest of hearts can be moved to tears; a tear in the ogre's eye
Proverb meaning that even a stern, unfeeling person can show emotion or be moved to tears under the right circumstances.
鬼の目にも涙で、あの厳しい部長が部下の送別会で泣いていた。
Even the sternest person can be moved to tears; that strict department head was crying at his subordinate's farewell party.
A traditional Japanese proverb. The exact origin is uncertain, but it draws on the image of an oni (ogre/demon) as a symbol of heartlessness.