And Yukio has his own revelation that he'd truly offended the trio of girls that had been trying to give him a lunch throughout the episode because he wouldn't even try their cooking.
Izumo is the only one to not care about the fact that Rin's the son of Satan. Rin is touched. Izumo is not.
Izumo's tolerance towards Rin then makes a lot more sense when the reader learns her backstory.
"Shiro, you weren't raising a weapon. You were raising a son."
After things are resolved between them, Rin has a flashback to his Rage Breaking Point as a child, when he hospitalized a classmate for calling him a demon. Shiro is patient and understanding even while telling Rin that what he did was wrong. Rin finally calms down once Shiro gives him a Cooldown Hug, but only after striking him once, having a My God, What Have I Done? moment as a result. Even better as Shiro was deliberately overselling how much the blow hurt, to better reinforce the lesson for Rin - only to subvert it immediately after the exchange below, as Rin's blow broke some of his ribs.
Shiro: Listen, Rin, if you don't change your ways, you're gonna find yourself alone someday. Instead of using your powers to hurt others, you should be using it tohelp them. I want you to have a bunch of friends, I want you to grow up to be a cool guy, the one the girls go crazy for. Young!Rin: What're you talking about? How am I ever gonna be someone like that? Shiro: You try. If you work hardand are nice to people, then before you know it you'll be that cool guy with all the friends.
ALL Chapter 11 and 12. Until Amaimon appears.
On a mission in an amusement park, Shiemi wishes that she could come again when they're not on a mission. Rin tells her that next time he'll go with her and Shiemi agrees.
When Rin is suffering from crippling self-doubt expressing itself in rage in Chapter 26, he receives a Cooldown Hug from Shiemi, who hugs him despite Rin being on fire at the moment, proving her trust for him and renewing his hope.
Fujimoto's contingency should he die and Kuro finds out - the wine they became friends over years ago.
Yukio: I just realized, there's absolutely no way dad would want to kill Kuro.
Episode 19 is this for everyone, as the class prepares to celebrate Izumo's birthday. She eventually finds out and chews them out for giving her special treatment, pointing out that they'd skipped others' birthdays that year, so it wouldn't be fair not to include them. Then Rin suggests just celebrating everyone's birthdays with one big party instead.
In chapter 19, when Shima argues with Rin for calling him uncool, Rin "proves" Shima is uncool by showing him his ranking of cool people. And who is number one on his list? My old man.
In Chapter 32, while Shiemi tries to save her, Izumo yells that she hates Shiemi. Shiemi's reply is that she still likes Izumo and thinks of her as a friend even if she hates her.
Chapter 44: In the previous chapter, Rin revealed his half-demon nature to Godaiin and later gave him the eye drops to get rid of his ability to see demons. In this chapter, Godaiin (who had been rather freaked out by Rin's revelation) reveals that he's held onto the drops, but hasn't used them. He explains that he's scared, but he has a dream, and friends and family. Rin is annoyed since he worked hard on getting the eye drops, but the two converse like friends anyway.
Chapter 47, despite probably wanting to dance with Shiemi alone, Rin decides to respect her wish to cheer up Yukio by having all three of them dance together. His thoughtfulness touches Shiemi greatly, although it just plain puzzled Yukio.
Chapter 66: Everyone stands up for Renzo, claiming they trust him. Somewhat spoiled by the fact not everyone is as happy as they claim there, but by chapter 68 they are all wiling to trust him despite everything and truly believe in him.
Chapter 67's conversation at the end between Ryuji and Renzo is chock full of a strong Friendship Moment as well.
Chapter 73 is a very good, sweet friendship thing that focuses on Rin and Shiemi's relationship. It's also where Rin finally confesses to Shiemi. Even if you don't ship it, you can't help but find his and Shiemi's reaction to that adorable.
Chapter 76, Rin utterly refuses to abandon Shura and calls her out on the fact she is attached to people. On top of that, though Rin doesn't understand, Shura claims he's already proven himself to her as someone worthy of Shiro's faith.
Chapter 80 has Shura finally free of her curse and thanking both Rin and Yukio sincerely, believing Shiro had planned for this and was looking out for the three of them.
In the same chapter as above, Rin makes bunny rabbit apple slices for his brother. And Yukio even eats them. The next chapter shows him learning how to control his flames enough to grill fish on the spot just to make it for Yukio.
That incident with the grilled fish? Yeah, Konekomaru readily and easily samples the fish Rin made with the blue flames. Now that is friendship from the guy who was the one terrified of Rin's Son of Satan status the most.
In the meantime, Shura outright assaults Mephisto in his office and threatens to kill him if his plans endanger either Rin or Yukio. Mephisto, true to form, calmly notes her Character Development.
Chapter 83. After being rejected by Shiemi, Rin reassures her they are still friends and will become exorcists together.
Also Chapter 82/83. The Kyoto trio see Rin get rejected and give him support afterwards.
In the movie, all the interactions with Usamaro, Rin, and the others.
And finally Liu being impressed with Rin and thanking him for showing him the miracle of opening a demon's heart.
Chapter 95: After he learns that Yukio has been detained for potentially having their flames, Rin decides to go rescue him. The other Ex-Wires immediately back him up.