This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / H2O: Footprints in the Sand
The whole second half of H2O: Footprints in the Sand, especially the last episode in which Hayami dies, just as Takuma recovers from his child-like regression and blindness. This is jarring, when you realize Hayami dies the same way as how Takuma's mother truly dies. I cried my eyes out for a full five minutes watching the rest of the episode, only to have them bring her back to life by grace of God. There was much tearful swearing, but plenty of relieved laughter too. In all fairness, it could have been worse (they could have left her dead). Which would have been totally pointless, as it was a bizarrely familiar series of events that triggered Takuma's recovery, making Hayami's death mere seconds later something of a kick the puppy moment.