The hero is a peace maker. Smoothing over conflicts between warring people. And sometimes this hits closer to home.
Our hero has two sets of friends. They both like him, but they are unfamiliar with each other. Maybe they have never seen each other. Perhaps they have good reason to avoid the other. Ultimately the two meet, and it can get violent. Neither side is inherently evil, they just don't know each other. They may be trained to think of them as the enemy, or they might think they are a threat to themselves or to our Hero. Perhaps one side is a peaceful member of the side that the other demonizes.
Our Hero demonstrates his peacemaking skills and steps in quickly to smooth things over between the two. He introduces the two usually say something like "He's a friend." He shows that they are not enemies. This usually leads to the two sides making up quickly. Or not.
In short, two of the Hero's friends are fighting/aggressive, then the Hero steps in to introduce them to each other. Compare Character Witness for when a less important character vouches for the hero.
- Princess Mononoke: Inverted. San explains to Ashitaka's pet elk that she is a friend.
- When Brandon Heat and Bunji first meet in Gungrave, they were in a middle of a gunfight and they ended up pointing guns at each other suspiciously but immediately stopped when Harry told Brandon that Bunji is working for him now.
- In Code Geass, not on the battlefield, but in high school - when Suzaku transfers into Ashford Academy, he wants Lelouch to pretend to not know him, to avoid causing trouble, but when the students react to Suzaku, Lelouch does one of these to help him.
- Young Justice's Collide has Robin assuring the rest of the team that an alternate dimension Jason Todd is a friend. Superboy was initially against the idea because Jason had earlier attacked Robin and "[he] don't like people who hurt [his] friends."
- In Origin Story, Tony Stark attempts to end the hostility between Superwoman and the Avengers — not to mention getting the Federal government off her back — by recruiting her into the Avengers team. The first non-hostile encounter between both sides goes pretty well, up until the point that Carol Danvers shows up and ruins it all with her bad attitude.
- The Incredibles: When Edna goes through her security system's identity check, a gun drops down in front of Helen, prompting Edna to quickly assure the system that Helen's a guest.
- The Iron Giant: Hogarth, Dean and Giant. "His name is Dean, we like Dean."
- How to Train Your Dragon:
- Hiccup says "She's a friend" to Toothless in order to calm him down and stop him from attacking Astrid.
- "Astrid, Toothless. Toothless, Astrid"
- The Lion King: Simba introduces Timon and Pumbaa to Nala.
- WALLE: Hal the Roach gestures to EVE that WALL-E shouldn't be blasted.
- In Thumbelina, the dog starts acting threatening toward the prince who came to visit, until the title character remembers and curtsies to him, telling the dog he's a guest, not an intruder.
Thumbelina: Oh! Ah, [curtsying] how do you do? How nice of you to come visit!
- Toy Story: After Buzz first meets Woody, several other toys appear. Buzz does a Diving Save on Woody and threatens the other toys with his "laser". Woody explains that the other toys are Andy's.
- Toy Story 2. When Andy's other toys arrive to rescue Woody from Al's apartment, they see Jessie tickling him and think he's being attacked. They charge in and threaten Jessie and Bullseye, but Woody defuses the situation.
Woody: Hold it now! Hey, you don't understand! These are my friends!Rex: Yeah, we're his friends!Woody: No, Rex, I mean they're my friends!
- Garfield does this for Odie and Luca after the former saves him by licking the latter. He said "Luca, this is Odie. Odie, Luca, Luca, Odie."
- Occurs in Terminator 2: Judgment Day, first in the hospital and then in a later scene in the extended cut where Sarah wants to destroy the T-800.
- In Mad Max: Fury Road, the Vuvalini get suspicious when they see men (Max and Nux) in Furiosa's War Rig. She placates them that "they're reliable".
- The Dresden Files:
Harry: [firmly] Be polite. She's a friend.
- In an earlier book, Harry had to do the same thing between Ebenezar and Kincaid. Ebenezar is Harry's mentor and one of the better father figures in his life; Kincaid an utterly amoral mercenary. The fact that Kincaid is willing to shoot Ebenezar is no big deal, but the fact that he has a reason to was definitely a surprise to Harry and the reader. Ebenezar's Dark and Troubled Past (and present) became a plot point from then on.
- In Thrawn: Alliances, Padmé Amidala gets entangled with a group of local workers on Mokivj and tells them that Anakin Skywalker is her uncle and can pay ransom for her. After she has found Anakin, one of the local workers sees Thrawn, who is working with Anakin, and makes to protect Padmé, telling her to look out. She tells him "He's a friend," but the guy considers this suspect at first, given Thrawn's unusual appearance.
- In Smallville, Clark tries to do this between his cousin Kara -alias Supergirl- and Martian Manhunter. It didn't end well.
- The Doctor has to do this for Rory in the series 5 finale of Doctor Who, since as far as River knows, Rory is an evil plastic-alien in the shape of a human. And while he technically is, he was human first.
He's on our side now.
Oh. I dated a Nestene Duplicate once. Swappable heads. Did keep things fresh.
- Turns out to actually be a subversion, since we discover half a season later that Rory was actually River's dad, and she knew exactly who he was, and was just pretending so as not to give away any spoilers. In retrospect, he probably wouldn't have appreciated the sexual innuendo.
- In the classic episode "The Invisible Enemy", K-9 initially regards Leela as a threat until Professor Marius, who had been helping the Doctor, informs K-9 that Leela is a friend.
- Halo 3: When the Master Chief jams a gun under the Arbiter's chin, Johnson stops him with:
- Done even earlier in Halo: Combat Evolved, where Chief tells Cortana this about 343 Guilty Spark after he and Cortana were separated for the previous two levels. And then promptly subverted, because Cortana rapidly fills John in on some things Spark neglected to mention. Like the fact that he'd nearly been conned into annihilating all living organisms large enough to targets for the Flood within a radius of twenty-five thousand light-years because It's the Only Way to Be Sure.
- Similarly done in the Mass Effect 2 DLC Lair of the Shadow Broker, when Liara pulls a gun on Vasir. Liara immediately declares that no she is not.
- Also happens several times if the player delays recruiting Tali to the point where they can bring Legion along. Maybe taking a Geth on a mission to rescue the AI-hating aliens from hordes of its identical evil cousins wasn't such a great idea, Shepard?
- This happens to Liara early in Mass Effect 3. After watching her efficiently double-taps Cerberus mooks, new squaddie James Vega approaches her with his rifle still up. "Easy there, Lieutenant. She's with us."
- In Paper Mario: The Thousand-Year Door, when Mario and Doopliss have switched identities, his partners are tricked into fighting him, and it doesn't help that Vivian (who had previously fought against Mario) is fighting alongside him. After Mario and Vivian defeat Doopliss, one of his partners asks him why Vivian is accompanying him. Vivian starts to explain, but Mario steps in and apparently tells them the whole story, convincing them to accept her.
- A subtler example in Dragon Age II. Fenris and Anders spend the entire game barely tolerating each other; Fenris strongly believes that mages (whom in this setting are inherently prone to possession) must be locked away in a Mage's Circle or even killed to prevent them from harming regular people, while Anders (who has escaped from such an environment) rejects the notion that locking mages away for life solves anything and actively fights for their freedom. Despite this, when another character points out that Fenris could just report Anders to the Circle to get him locked up again, he rejects the idea:
Fenris: I don't [trust him]. But Hawke trusts him, and I trust Hawke.
- Done in Wolfenstein: The New Order when B.J., Anya, and Fergus or Wyatt first arrive together at the Kreisau Circle headquarters, and B.J. tackles Klaus to the ground on sight because of the swastika tattoos on his shoulders. Fergus/Wyatt then has to explain that he used to be a Nazi, but things happened and he isn't one anymore.
- Batman Beyond: Bruce's dog, Ace, takes some time to warm up to Terry.
- Jackie Chan Adventures' second season, when El Toro, a one shot ally from the previous season, turns up, he attacks Tohru (since the last time they met him was before his HeelFace Turn) until the situation's explained.
- Jonny Quest TOS.
- "Werewolf of the Timberland". The wolf Gray One has just saved Dr. Quest and Race Bannon from being attacked by the "werewolf" (a man in a werewolf suit), but they don't realize this and Race Bannon prepares to shoot the wolf. Jonny and Hadji arrive and call out to them, telling them that the wolf is a friend.
- "Calcutta Adventure". Pasha Peddler shows up in his helicopter right after the team has been attacked by a mook in a plane. Race thinks he might be an enemy, but Hadji tells them he's a friend.
- Avatar: The Last Airbender: Sokka has to do this for Zuko twice during "The Boiling Rock," once for Suki, who remembered him from when he destroyed her village, and once for his father Hakoda.