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Tear Jerker: Kingdom Hearts 3D [Dream Drop Distance]
The first cutscene involves Terranort watching as Even and Ienzo fade into darkness. Ienzo is a child, and his little body lying next to Even's...
For an opener that runs pretty quickly over the main parts of the game series thus far, the fact that they decided to include Xion's mini-flashback to when she, Roxas, and Axel were eating sea-salt ice cream atop the clock tower - and the subsequent smirk on Xion's face that lasts about a half second before she disappears - says a lot about her significance to Roxas' story, especially since Roxas' part of the opener purely consists of Xion and Axel. It practically yanks at the heartstrings because despite her significance, anyone who's played 358/2 knows that NOBODY WILL REMEMBER HER AT ALL.
The Grid. Don't let it's cool appearance fool you. It's the second saddest world in the game, behind only The World That Never Was. Of the characters found here, only two survive to the end. And not only that, many, MANY, fans cried after defeating the boss in Side: Sora.
The look on Lea's face when Isa attacks him while he is rescuing Sora.
And for that matter, the revelation of what reallyhappened to Isa after he became a Nobody.
From the ending bits of Kingdom Hearts Dream Drop Distance: It's gut-wrenching seeing Sora end up exactly like Ventus. Sure, Lea comes in as a Big Damn Hero and saves Sora from becoming a Xehanort clone, but again, Sora=Ventus right now. Comatose with a shattered heart teetering on oblivion. It was scary finding that we were so close to losing him... to losing EVERYTHING...
And finally, when a comatose Sora is brought back to Mysterious Tower, Mickey worries that things are repeating with what happened to Ven. It shows that Mickey has never really gotten over what happened back in Birth by Sleep, and the he's worried to loose someone else the same way as Ven.
The chronicle summarizing Days basically confirms Xion's suicide attack, stating: "The two fought and Xion got her wish: she was defeated."
After Sora defeats Xemnas, he is absolutely winded. Peppiest guy in the world, never shows he's tired for a second, actually allowing that shell to crack. Even worse, his heart has finally snapped, and has given into the darkness, ending his side of the story in the most tragicway possible.
After Sora meets Roxas, he is made to know what happened in 358/2 Days, much like what happened near the end of coded. However, it's even sadder than the equivalent scene in coded. Sora is basically staggering under the weight of all that he just learned, and he comes out with this line:
Sora: Not again... Did they cause all this pain...? ...WHAT DO YOU WANT ME TO SEE?!
This troper honestly expected to see Sora cry. The anguish in his voice over seeing those memories is... Just hearing that sorrow and frustration coming from Sora is just plain murdering a heart.