The crossover episodes with Samurai Sentai Shinkenger have Crowning Moments Of Heartwarming for both the Shinkenger team and for Decade's group, the two biggest being when Natsumi welcomes Tsukasa home at the end of the second episode, and also another one from Shinken Red: "I don't know about the world, but we have no intention of driving you out."
Arguably, the interactions between humans and Fangires in the World of Kiva arc. Most of the Fangires are in their human-looking forms but freely displaying stained glasses on their faces. You can see them in a group of friends with humans and some are even lovers.
During the opening, we see Tsukasa sitting on the ground with tears in his eyes, and an arm in a brown jacket hands him his camera. Then Daiki Kaito shows up. What is he wearing when he turns up in the opening? A brown jacket.
Kamen Rider Ichigo: So long as there is evil in the world, we will never disappear!
Despite Wataru saying that Tsukasa role is fulfilled and thus he has no reason to exist and all the trouble that Tsukasa caused during his rampage as Violent Emotion, his friends and the AU Kamen Riders refused to give up on him and together they revive him with their memories showing just how much they care about him and trust him.
The ending of the Decade saga: Tsukasa has connected and reconstructed all the worlds he destroyed, ensuring the safety of the multiverse. Having been brought back to life and his role complete, he can now go on an endless journey doing whatever he wants with his friends. The series ends with a new background on the studio wall unfolding into an endless road, and him sharing a final (actually well-developed!) picture with his friends.
Despite their somewhat not-perfect relationship and events throughout the series sometimes make her question things, Natsumi refused to fully turn her back on Tsukasa and while at times he annoys her she truly comes to see him as a friend and maybe something even more. While others began to doubt him, she rarely turns her back on him.