Steins;Gate/Heartwarming

Anime

 * The relationship between Okabe and Mayuri can be summed up as this; they grew up together from a young age, and share a bond that is akin to brother and sister. Okabe in particular is always wary of Mayuri's safety, while Mayuri is always looking out for Okabe's happiness and wellbeing.
 * Episode 3: Mayuri's excitement upon discovering that there is another girl joining Future Gadget Lab. First thing she does when Kurisu introduces herself as the newest Lab Member? The former runs up to her and gives her a great big hug.
 * In Episode 9, Kurisu bursts into tears after an argument she had with someone over the phone. As she sobs into Mayuri's Oopa cushion, Okabe tells her that he values her as a friend, and she can tell him anything. Now granted, he only said that to bait a reaction out of her, but even still, she is no less touched by this gesture. She brings this up later during a confession she makes to Okabe, so what he said wasn't just some throwaway line.
 * Even better is that Okabe reveals during a power outage that his inability to make friends is the reason he formed the Future Gadget Lab in the first place. Kurisu also tells him that while the FG lab is nothing compared to what she's used to, she admits that she feels more at home here than anywhere else.
 * Episode 10, Kurisu decides to open up to Okabe about her strained relationship with her father. He, in his usual goofy fashion, offers to help mend her broken relationship with her dad by offering to take her to him to patch things up. It is another touching moment between the two characters. Until...
 * ...Cue Mood Whiplash though as the next scene they're in, she's scolding him for eating one of her snacks!
 * Many interactions between Okabe and Kurisu in the second half of the TV series, particularly:
 * In episode 14, when Kurisu makes a Mad Scientist impersonation (complete with Insane Laugh) in order to cheer Okabe up.
 * In Episode 16, Daru tries to get a copy of the badge Suzuha gave Okabe in order to give her some hope of finding her dad by at least pretending to fill that role. Granted, he'd be lying to her and giving her false hope, but he had good intentions, so it is hard to fault him for that.
 * Turns out
 * In episode 22, the whole scene where Okabe.
 * In episode 23, when Okabe meets Kurisu again . Doubles as Tear Jerker.
 * Episode 24 ended with all of the side cast closure, and wrapped up their arcs nicely, with Okabe giving all of them Lab Member badges, which are inscribed with each member's initials.
 * He even gives one to Moeka, keeping his promise of forgiveness for her transgressions in other world lines.
 * He also keeps one badge in a box for
 * The final line in episode 25, an obvious Call Back to episode 22

Film

 * Okabe invites the gang over for a rooftop barbeque. His reason? He heard "a certain wayward assistant" was back in town.
 * Though she was drunk at the time, it was lovely to see a softer side of Kurisu, as she starts flirting with Okabe, rubbing his cheeks, and cuddling him.
 * Mayuri tells Okabe about the dreams she'd been having in which she died over and over, with him there to save her. In another touching moment between the two, he tells her not to think about it, and he proceeds to hold her in his arms, which Mayuri is grateful for.
 * It turns out that Kurisu did get Okabe a present after all: a fresh lab coat. Cue her ever present Tsundere act afterwards, but still.
 * In fact, one drama CD (forgot the name of it) that takes place a week before the movie all but confirms this. Both are shopping for a present to give each other when Kurisu eventually arrives in Akihabara, they seeks advice from Mayuri, who quickly realises they are looking for gifts for each other, once again despite their denials.