After seeing everything Michiru went through on the way to Anima-City, seeing her goofing around having fun at the festival is a very welcome sight.
Michiru teaching the children at Rabbit Town how to read and write. The kids aren't an army of brats who makes life hell for the poor girl. While they start out a bit disinterested, they get excited when she teaches them to write their name.
Michiru's parents. Even though they're never shown, from the few looks into them we get they still clearly love their daughter. Enough that Michiru felt terrible for running away and for her mother baking her a cake for her birthday even if she couldn't eat it.
The ending of the Baseball Episode. The Bears might have lost the game, but they reminded Anima-City what baseball is really about and rekindled Dante's love of the game, leading him to quit gambling. Plus, it shows Michiru starting to fit in with the city by befriending the Bears and acting like a big sister figure to them.
The manner in which Dante is redeemed is heartwarming in and of itself. Shirou confronts him making off with the stolen gambling money, but rather than a beatdown, he simply pulls out a radio and has Dante listen to his team playing in earnest, reducing the broken man to tears.
Michiru's relationship with Shirou evolving from two individuals who can barely stand to be in the same room together to Fire-Forged Friends who trust each other unconditionally.
All of Anima City teaming up to stop the anti-beastmen drones and save the city from the Nirvasil Syndrome in episode 12. Michiru and Nazuna rekindle their friendship completely, Flip forges a temporary alliance with the police to protect "his" city, the Bears bundle together to help the heroes spread the cure and even Pinga swings back around to help evacuate unaffected citizens to safety.
Michiru comes to accept herself as a Child of Two Worlds. She and Nazuna aren't human or Beastmen but ones who understand what it's like to be both, and plan to help build the bridges between the two races.
Despite most of the beastmen feeling betrayed by Nazuna’s true identity, the Bears still help her out, because Nazuna gave them bread and to the Bears, anyone who gives them food is a god.
One of the closing shots in the final episode shows the corridor where anti-beast humans graffitied an old poster promoting beastman and human unity in the first episode, only now with the poster is replaced with one of Nazuna promoting Anima-City, clean and untouched, implying that her efforts are already making a difference.
