* Every instance of Aang and Katara calling each other "sweetie". [[SickeninglySweethearts Ooginess]] aside, it really shows how far they've come since their first meeting.
** Also the subtle nod to their RelationshipUpgrade with Aang's new glider--which he and Katara fly on together--colored Water Tribe blue.
** One heartwarming scene in The Promise part 2 is at the beginning, when Aang and Katara nestle up beside each other.
* Sokka found Boomerang again, after losing it during the airship battle!
* This moment from Part 2 was so heartwarming, it made ''Toph'' tear up:
-->'''Ho-Tun:''' Sifu Toph, you're the first person to believe that we can become '''more''' than what we are.
* Suki telling Zuko she's worried about him; this guy burned down her village in Book 1 so it's great to see them on such good terms now.
* In Part 3, Katara blows away every imaginable argument over whether or not she's suited to be Aang's "Forever Girl" by instinctively defining the heart of the conflict around them in a handful of sentences. Doubles as a [[Awesome/AvatarTheLastAirbenderThePromise Crowning Moment Of Awesome]] because doing so not only keeps Aang from repeating Roku's mistake and starting the war up again, but lays the foundation of WesternAnimation/TheLegendOfKorra's [[TheFederation United Republic Of Nations]].
-->'''Katara''': On our first visit to Yu Dao, when I saw Kori's family--''(a Firebender and his Earthbender wife HappilyMarried with an Earthbender daughter)''-- I also saw '''our future'''. ''(shows Katara and Aang in their twenties, with Katara holding a baby)'' If the nations have to be separate, what will that mean for '''us?''' I... I know it's selfish of me to think like this. There's so much more at stake than just us. Go find a quiet place, Aang, and figure this out. Then, whatever decision you make, I'll trust that it's the right one. I'll support you. Even if it means you have to fulfill your '''promise.''' And even if it means we have to be '''apart.''' (awesomely emotional kiss)
** It's also a great marker of their RelationshipUpgrade; in the penultimate episode of the series ("The Ember Island Players") she refused to confront her relationship with Aang during the culmination of the Hundred Year War, feeling that whatever was between her and Aang was not important when a more larger-scale issue was at hand.
* When Aang admits that Zuko was right about Yu Dao; all that drama and they're still friends.