The episode wherein Hamaji befriends Suzu at the girls' boarding school tops most of these moments showcased thus far in the show, thanks to Shino's wish bringing her to life.
Before that, let's not forget that Hamaji's attempt on befriending Ayane in several episodes earlier. It's also thanks to their friendship that Chikage defrosts.
Dousetsu's confession to Yukihime, and his resolve to find his lost sister, could be seen as incredibly sweet as well...if he could figure out where she was. (Regardless, the scene with Yukihime is still heartwarming.)
The fact that Yukihime sacrificed her voice to save him because his resolve reminded her of Shino, who was her Only Friend until then.
Sousuke and Shino's relationship in general, platonic or otherwise. Sousuke acts as if he were Shino's mother, or at least an extremely protective older brother. He is constantly advising Shino to be careful, to keep up his strength, and isn't adverse at all to sacrificing small things for him and carrying him around as if he were five years old. Shino adds to the act by being himself, and also displays frequent moments of affection.
Kohaku and Shino's interactions. She seems him as a small angel and he sees her as someone he wants to live deep in his heart. This becomes a Tear Jerker in episode 12 when Kohaku has to be Mercy Killed by Shino to prevent her from losing her humanity even further.
Princess Yana's guardians begging her not to leave them.