Chika helping Kuga ride a bike. Seeing the two interact for the first time is cute, especially knowing that they're going to be teammates later on.
The Tamakoma Branch accepting Yuma into their fold even though he is a Neighbour.
The Shinoda faction siding with the Takakoma Branch in protecting Yuma.
Border Enlistment Arc
Kinuta praising Chika an when he sees Osamu gruffly tells him to look out for her, showing that he isn't as bad a guy as he was implied to be at the beginning.
Kazama says that while Osamu is weak, he likes his fighting style. Makes sense considering that Kazama is leader of [I]the[/I] No.1 Stealth Unit in Border, which requires a good head in order to reach their full potential, but its still sweet that he's encouraging Osamu in his own way.
Large-Scale Invasion Arc
Even though he thrashed him, Shun wears a new battle uniform similar to Kuga.
"I'm not on his side, it's just a hero should always be given an opportunity to fight back, correct?" And to make it awesome, Osamu does fight back hard.
Osamu calling Yuma partner judging by the surprised look on Yuma's face you can tell that it means a lot to him considering the fact he just recently lost Replica (his first partner).
Commander Kido talking to Osamu and his genuine interest in his health and welfare.
Osamu, Yuma and Shiori teaching Chika to value her own life. When Reiji learns of their efforts, he also joins in the attempts.
Kikuchihara helping Osamu with training and pointing out that not to disappoint Kazama with his next fight, as he has high hopes for Osamu. Seems that their earlier sparring match and Jin's praises had left quite an impression...
Tokieda noticing Kikuchihara talking with Osamu let alone to someone outside of his unit is rare.
When he is a color commentator Shun calls Kuga 'Sempai', and Osamu 'Captain'.
Ko is worried that his Rapid-Learning Side Effect "stole" Arafune's hard work and drove him to quit being an Attacker. Arafune, who had already been planning to switch to being a Sniper beforehand but didn't want to sound like he was making excuses, records a message telling him not to blame himself. In fact, After achieving mastery as a Sniper and Gunner, he plans on teaching that to Ko as well.
Ko's leader Kurama is pretty sweet too, to his team. When Ko was feeling down thanks to the above incident, he went [I]cycling through the rain[/I] just to ask for Arafune's side of things. Most people would normally just ask over the phone or something. And when Arafune said that it wasn't Ko's fault, Kurama recorded it down to give Ko proof that Arafune wasn't mad at him, and then gave some words of encouragement too. With that and him not getting mad at Taichi despite destroyinghis tropical fish when he had all right to, its clear that he cares for his team. With his naturally sweet and good demeanor, its no wonder that he's earned his team's respects, and charmed many others besides.
The Kakizaki Unit can bring up some feels, too. Kuniharu Kakizaki, Leader of Kakizaki Unit, reveals that [[Self-Depreciation he believes that his teammates deserve better than what he can provide]], and that they are better than what Border thinks they are capable of. His entire monologue on how he feels and thinks about his teammates, and how that even though there will always be new recruitswho might overshadow them, they will always be together through thick and thin, is quite sweet and brings some happy tears to the eye. Even better is that his doubts about his leadership are somewhat unfounded, as it is clear that his team respects him and like the way they do things.
Hyuse an Yotaro's relationship in general.
Once he leaves Tamakoma HQ he looks back and says 'goodbye big guy'.
In a Flashback Jin asked Yotaro - what if Hyuse wanted to return to Afto Krator? Without hesitation, Yotaro says that he would let Hyuse go home even though the look on his face implies that he was sad at just the thought.
Hyuse being unwilling to kill Yotaro, even if doing so would let him return to Afrokrater.
When Hyuse's enlistment in border is officialized Kuga tells him to call Osamu 'Captain', proving that even after all this time he still thinks that Osamu deserves the title.
in Chapter 149 Netsuki reveals he regrets framing Osamu in the press conference when Osamu uses on of his tactics in the meeting. He even says Osamu has learned nothing good from him.
In Chapter 163, Yuzuru offers to basically throw Kageura Unit's upcoming fight against Tamakoma-2, to help ensure Chika goes on the next expedition. Yuma not only explains that Chika is already guaranteed to go(because by using her as a Living Battery, they can make the Trion ship bigger and thus send a bigger expedition), but he and their friends also convince Yuzuru instead to fight his best, so he can go on the expedition and protect Chika himself.