This is based on opinion. Please don't list it on a work's trope example list.
Tearjerker / Disgaea 4: A Promise Unforgotten
The full backstory of Nemo. Born in a country torn by war, he became a young soldier skilled in fighting. Then a defeat caused his country to declare him a spy, and his family was killed before his eyes for his actions, and he was cast out. He eventually wandered to the border between countries, dying of dehydration and malnutrition where he was rescued by Artina, even though she worked at a camp of the enemy country. She brought him back to health and restored his hope, but then HER country declared her a traitor for helping an enemy, and executed. And Nemo got captured and tortured AGAIN, being forced to live despite wishing for death. This sent Nemo into the depths of despair, yet despite his anger and thirst for revenge he resisted his dark desires. But he had lost faith in God, and was unable to hear the voice of Artina who had become an angel. Eventually his hatred grew so large that his soul avoided Death even when his body had died and crumbled to dust. You just want to give the man a hug.
As bratty as he was for the first three chapters, Emizel really goes through the wringer in Chapter 4, you feel pretty sorry for him as it goes on. Thankfully, it's for the better, and he starts his Character Development as a result.
It's meant as sort of a gag about how Fuka and Desco haven't gotten used to each other, but Desco's so sad that Fuka calls her gross at the beginning of Chapter 4 that it's hard not to feel bad for her.
As with most things, the Axel apocalypse bad ending is played for laughs, but you gotta feel for Artina in that scene. Having to watch your new friends (...and Fenrich) and even Valvatorez, her Mr. Vampire, turn into Axels is pretty horrible, even more so because she's unable to do anything about it. They even gang up on her when they see she hasn't changed. The credits just rub it in even more, with the whole party rocking as Axel, while Artina lies wounded on the side.