The Karate Kid/Tear Jerker

Original films:

 * Mr Miyagi's entire backstory, from leaving the one he loved to leave a death fight, to marrying but forced to go to war thanks to racial prejudices, only to lose his wife and unborn baby to childbirth while in combat.
 * Miyagi's father's death was pretty sad too. The last thing he does before dying is place Miyagi's hand over Sato's, silently begging them to end their feud.