The scene that Queen Horne reunited with the real King Horne after she gave birth to Aire and didn't die.
Jusqua's massive obsession with helping (Whom he thought to be) Aire turn back to normal, despite he didn't give a crap about her earlier and outright told her he didn't give a crap about her. It just shows how much he really cares.
Aire and Yunita reuniting in Spelvia's dungeons, with Aire apologizing to Yunita for being a Royal Brat and asking Yunita to be her friend rather than her knight.
The scene after the Climax Boss, when all four kids get together for the first time since Horne was cursed. After bumbling around, being jerks to one another, and generally not acting at all like Hero of Light material, they all come together as friends with a real determination to save the world, even in the face of darkness spreading over the world—a bigger obstacle than any they've faced so far. It's immensely satisfying to see them become True Companions and prove that the Crystal chose right.