The entire ending theme is a showcase of Blank's sibling bond and has uplifting music sans the version in Episode 8.
Episode 1: As Sora and Shiro are crashing towards Disboard, Sora's first instinct upon almost hitting the ground is to shield Shiro so that he receives the brunt of the impact.
After going too far with the insults towards Stephanie's grandfather, Stephanie runs off in tears. Later, Jibril asks Steph to come back to the library, where she finds Sora desperately trying to find a reason why the former king challenged the Warbeasts eight times. He does. It leads to Sora genuinely complimenting the former king and Steph breaking into Tears of Joy.
Sora's reason for why he thinks that Humans Are Flawed yet still believes in human potential. It's because he believes in Shiro, by virtue of being the only person who saw past his empty smiles and saw the real him.
Episode 9:
Shiro refuses to remove the memories of her brother, even when presented with the possibility that he may have never existed and clearly hurting from his absence.
Sora's absolute trust in Shiro that she would win the game even if he disappeared. And she delivers
The three last priorities that Sora left behind as game piece? The plan to win, his absolute trust in Shiro, and his memories about Shiro. These rank above his own existence.
Back in Episode 3, Sora joked that Kurami would look cuter if she smiled. After Sora wins the game and returns her memories. She does
Shiro's reaction when Sora expects her to punch him after the emotional turmoil he put her through is, instead, to cling to him and apologise for not figuring out his plan sooner. Moments later when Sora mockingly threatens to make his demands, Fiel throws herself over what is essentially a brain dead Kurami. Even knowing it's utterly hopeless as Sora could permanently erase Kurami from existence, Fiel still desperately attempts to protect her.
Episode 10: Lots of sweet moments between Feel and Kurami:
As children, they ate together despite the stigma between their classes.
During the "introductions" Kurami introduced Feel as her "friend" first and her "master" second. Based on their following interactions, Sora decides that "mother" is more accurate than either one.
Fridge-Hearmwarming. Why was Kurami so insistent that she wouldn't be a Puppet King back in episode 2? Even though Kurami was a slave, Feel treated her like an equal.
Episode 12: Sora and Shiro welcoming Izuna to the Gamer Community. She clasps one half of Blank with each hand, and to cement their friendship, they do a Furo Scene. Much tail fluffing ensues.
Volume 4:
After sniping at each other for much of the book, Sora and Ino have a Friendship Moment following the latter's Heroic Sacrifice. Sora even declares him to be the manliest of men.
After hearing the plan behind their attempt at the Siren's game, Stephanie is outraged at the idea that Sora sacrificed Ino for information. Sora is even more outraged that she would accuse him of such a thing; rescuing Ino from the Sirens was always part of his plan, if for no other reason than to keep Isuna from being sad.
The Human Colony's loyalty to Riku. Even though the Light Novel and Movie both deliver how soul-crushing it is for Riku to send people to their deaths, anyone who does has done so with a smile on their face, knowing that their leader wouldn't let them die in vain. It's a stark contrast to Blank's way of going about relationships with Elkia, because Sora constantly builds up an image of untrustworthiness, while Riku was trusted from the very beginning. Even the formation of the Ghosts shows Riku noting how this entire thing is stupid, only for the Ghosts to agree and go with it anyways, because they're happy to support a cause that's worth dying for.
Corone's relationship with Riku. Unlike Stephanie's status as a Butt-Monkey to Sora and Shiro, Corone is shown to be treated as an equal to Riku and Shuvi, where they both respect and hear Corone out on a lot of her worries. Hell, even when their plan to upstage the other Races is already in motion, the animation delivers in their hesitance about their actions when Corone starts crying in front of them.
Riku falling in love with Shuvi and proposing to her in the middle of the film. It came after such a tense time to where Shuvi was so surprised that he could love her, a discarded Ex-Machina, that she confesses that she was the one to destroy Riku's original home. He doesn't care and wants her at his side anyways.
Also, the informal wedding reception that follows with Corone serving as the priest. Even when Shuvi is revealed as an Ex-Machina, Corone without hesitation still puts the honorary flower in Shuvi's hair and respects her because she is the person Riku chose to be his wife, fully embracing her as family.
Finally, despite Riku and Shuvi both dying, Tet is successfully born into the world and brings about the peace that both wanted. And Tet never forgot them. Neither did Corone, because the gem that she used in honoring Riku and Shuvi's marriage is the exact same jewel that Stephanie wears on her brooch, having been passed down as a family heirloom for over 6 millennia.
Surprisingly enough, despite Jibril essentially being a villain in this movie through her killing Shuvi, the epilogue in the present day shows that Jibril remembers the battle with fondness and respect. She goes out of her way to take back her original remarks of Shuvi being "scrap metal" and declares her an enemy worthy of her full power. For Jibril herself, being the battle-hungry Flugel she is, that says a lot.
