Warning: Spoilers Off applies to Heartwarming pages.
First Chapter
The immediate aftermath of the school play, where Jill reveals that the school has been running a donation campaign so Theresa can rebuild the orphanage that means so much to her. Doubles as a Tearjerker.
One of the more unusual examples of this is the scene where Estelle and Joshua have an extended conversation with Colonel Richard over drinks. He reminisces about what a great hero their father was, to Estelle's surprise, and how he saved the entire kingdom from ruin in the Hundred Days War. When he sees them arguing, he simply chuckles, remarking that maybe the two helped him recover from this loss of his wife. Normally, this would be a touching bit of exposition, except that the two had previously seen him taking Tita's grandfather Professor Russell hostage in order to learn more about the ominous Black Orbment, so it becomes an awkward case of Mood Dissonance to see the villain of the game talking in such a sincere and kind tone. It also becomes Harsher in Hindsight considering his obsessive hero worship is what drove him to villainy in the first place.
The climax of the game has Estelle and Joshua's father, Cassius Bright, who they had been searching for the entire game, finally show up to pull a Big Damn Heroes moment on the Final Boss. He will also address whoever is in their party at the time. A fan favorite is his message to Tita, where she tells him Estelle and Joshua treated her like a little sister, and Cassius replies, "Welcome to the family."
While it only compounds the tragedy of the ending, Joshua's Love Confession to Estelle is rather touching, even if he is abandoning her.
Joshua: You had me from the first moment I met you. I've always loved you. Goodbye, Estelle.
Second Chapter
Oddly enough, one of the chest quotes.
You know the chest is empty, but it has served you well. Instead of opening it, you give it a gentle pat on the head.
During the prologue, when Estelle is returning from Grancel, she's visibly shaken and vulnerable. Noticing that, Kevin tries in his own goofy way to cheer her up. When she lets it slip that she's looking for someone who's clearly important to her, he quickly puts two and two together and offers to accompany her home. At the time, he has no idea who Estelle is or what happened to her, but decides to stick by her all the same. What really makes the thing very heartwarming is how realistically Estelle's reaction is portrayed: the way she acts and the subtle clues Kevin readily picks up on would definitely not be out of place from someone whose brother ran away from home. And Kevin decided to be a good samaritan and help this complete stranger who was clearly extremely distraught that someone important to her had disappeared.
When Estelle is aboard the Linde in the beginning of Chapter 1, talking to the staff and passengers shows that they recognize her as a Bracer, some even remember her from FC when she helped rescue them from the Capuas. They are nothing but thankful for her help, and a few remark that they feel better knowing she's there. It's heartwarming to see that Estelle's finally earned the respect she's always wanted, and she's treated with the same honor and admiration others had for full-fledged Bracers like Schera and Zin.
Passenger: Bracers like yourself always seem so busy, Miss. It must be so rough...Still, it's because of your efforts that our lives are peaceful. Thank you!
The reunion scene between Estelle and Joshua, regularly cited as one of the favorite scenes in the series in official polls.
During the end of Chapter 8: first, Alan Richard and Kanone Amalthea swoop in an awesome Big Damn Heroes moment, saving Grancel, the Queen and our protagonists, showing that they have become proud allies of good, then, after the danger is passed, you receive frightening news: the Erebonian army is marching towards Liberl, and they conveniently already have steam-powered tanks. Then, you find Olivier, of all people, leading them. Oh, and he's apparently an Imperial prince. He gives all the impressions of having played you and your group for fools all that time, betraying you at the worst possible moment... then, Estelle stands up to him and it's revealed to have all been a plot by Cassius and Olivier to delay the Imperial invasion. And not just that, but Olivier is actually planning to overthrow the Evil Chancellor of the Empire and goes on to deliver a heartwarming speech about how he wants the Empire to be a power for peace, remembered for its accomplishments, not for its violence. Goes to show that, deceptiveness aside, Olivier has always worked for the good of all, and always was a genuinely good person.
Axis Pillar has two of these. First, Estelle giving Renne a Cooldown Hug. Which works. Second, Joshua and Loewe's reunion after the former persuades the latter to leave Ouroboros.
Seeing the other members of Ouroboros mourn Loewe in their own ways in Loewe Monogatari is pretty heartwarming
Is The Dream Continues playing in the background? Best prepare to have your heart melt then.
The flashback in the Mistwald Forest to Estelle's childhood yanks on the heartstrings pretty darn hard.
The dialogue following the final boss during the Collapsing Lair sequence. Estelle, facing her and Joshua's imminent demise, asks him for two requests: to hold on to her tightly and to kiss her one last time. They do so, as the platform they are on crumbles. Adorably, if you watch closely, you can see that as they start to fall to their apparent deaths, they are still holding onto one another.
During one of the airships intermissions, Olivier is talking to Mueller after the latter's fight with Joshua,which Estelle overhears. He tries to cover it up by being his usual self, but Estelle sees right through it. What makes this heartwarming? Well, after saying that she doesn't really know all that much about Olivier and that he's really suspicious, she says that she trusts him anyway and says he is an important part of the team. Olivier is visibly touched.
All of Scherazard and Estelle's interactions during Chapter 4, with the former guideing in the best Cool Big Sister manner, while the latter tries to support and cheer Schera up as best as she can.
The 3rd
The entire premise of Moon Door 5, where the orphans at Mercia look for a birthday present for Theresa.
Estelle's indefeatably enthusiastic attempts to cheer Joshua up shortly after he arrived at the Bright household, primarily by trying to collect as many interesting insects as she could find until she got one that could catch his attention. She never found the right bug but wound up catching his attention anyways when she caught a swarm of bees by accident.
In the final dungeon, many of the chests have messages from XSEED Games thanking the players and wishing them good luck in beating the game.
When Renne is released into Phantasma, she's fast asleep and when she wakes up her first reaction is to assume that she's dreaming. As she notices Estelle, Joshua, and Tita, she sleepily comments that it must be a nice dream. Only when Estelle runs over and hugs her and Renne notices how warm she is and how nice she smells does she finally realise that she's not dreaming.
After beating Schwarzritter/Loewe, attentive players will notice an illusion of Karin (Joshua's dead sister and Loewe's love interest) appearing behind him for a split second before he disappears for good. It's almost as if she's welcoming him to be Together in Death.
The entire scene following Schwarzritter's defeat is one, and even more depending on who you bring.
Joshua deducing that the entire reason behind Loewe's Paper-Thin Disguise was because he doesn't wish to lose him another time. And in the end, he finally manages to finally say goodbye to Loewe instead of being a crying mess like in SC.
If you bring Agate, Loewe will start complimenting him for his swordmanship and Character Development, and when Agate responds that he still has a long way to go. Loewe is genuinely surprised.
Finally if you bring Renne, Loewe starts by apologizing as he never had the chance to say goodbye to her. Renne assures him it's not his fault, and that she would never hold a grudge against him as he and Joshua saved her from Paradise. She ended by saying that she will always be grateful to him for what he's done. All he can answer is thank you.
Kevin's reaction when Ries is dropped off to Gehenna. He breaks out of the space bind with his stigma, and jumps into the cracks after her.
The fact that both Kevin and Ries are willing to go to hell for each other is really sweet and amazing at the same time.
During the final scene before the credits, as Olivier is about to leave Phantasma with Mueller, it is (strongly) implied that he proposed to her offscreen. It's no secret by now that the womanizing debauchee is an act he devised long ago to make sure everyone would underestimate him, but the thought that he's prepared to commit to someone is still very touching. Doubly so when you consider that Schera was an abandoned child who grew up in a slum, both resenting the upper class citizens, yet also wishing she were one of them, and accepting his proposal would make her a bona fide princess.
playing in the background? Best prepare to have your heart melt then.