- Rock and Revy have some of them:
Revy: Rocky, baby, you been a good boy? [Rock smiles] If you promise to behave yourself a little bit longer, sweetie-pie, I'll even buy you some cotton candy!
- After their massive argument which nearly ends with Revy shooting Rock, they share what's almost a tender moment in the back of a patrol car when Revy gets Rock to give her a light by leaning close together and pressing the end of her cigarette against his. (This is such a perfect example of that trope that it STILL provides the page pic.)
- The way the two of them treat each other in the final story arc of season 1 proved to be quite heartwarming. Revy's rescue of Rock is a good example of this; before it happened, she spent most of her time competing with Shenhua for kills and gunning down JRA soldiers without any resistance whatsoever. When Revy breaks down the door between her and Rock, she's understandably feeling more confident than usual, so she decides to greet him in a way that is impossible to distinguish from flirting.
- The rest of the rescue includes things like: Revy showing genuine concern for Rock's well-being, getting sad when she thinks she's made him feel worse, and Rock blushing and stammering when he tries to thank Revy for rescuing him. Then Revy tells him to knock it off on account of them being friends, then punches him and starts yelling at him for how much she had to go out of her way to rescue him... which only makes poor Rock blush even more.
- In the manga, when Revy asks Rock to tell her why she has to always go along with what he wants (with a lot more swearing) Rock gives a little speech Back in my country, you called yourself a gun. If you're a gun, then I'm a bullet. A bullet's just a lump of lead. But, once the hammer hits it, that lump of lead gains the power to blow anything away. If we had never met, then I would have spent my entire life as just a lump of lead. But, we did. The gunpowder was always waiting to explode. And the only thing that can ignite that gunpowder is a gun.
- The scene where Revy plays with the little Japanese kids. It's cops and robbers and she's showing them how to fake die realistically. Then her reaction when she realizes that Rock was watching the whole thing was just priceless.
- At the end of issue 34, Rock and Revy revisit the kids and Rock gives her the nod to demonstrate her can trick with her Cutlass. After she ... impresses ... the kids she turns and gives Rock a small, almost bashful smile. After everything they've been through in Japan so far, she's willing to briefly show a little bit of simple happiness to Rock.
- The penultimate episode, when Rock is able to convince Balalaika, the series resident dissonantly serene, hyper-violent magnificent bitch Death Seeker to not only let him and his friends live, but to help them take down the Kosa Council, simply by reasoning with her, proving that even in an utterly bleak and morally desolate world like the one the series takes place in, it's still possible to solve your problems by talking it out.
- Balalaika gets a second Heartwarming Moment in the twenty-second episode, which contains a flashback to the Afghan War that has the young Balalaika looking through the scope of a sniper rifle, scanning for potential targets. She sees a young woman holding an infant standing out in the open with no cover: a perfect target. Only, she passes right over her, and takes a much more difficult shot on a man holding a gun.
- The final battle in the last episode is a twofer: Ginji slows down when Yukio admits the only reason she went through with the whole Yakuza thing was only to be with him forever, giving Revy a window to finish him off. His last words in the dub? "Yukio..."
- The second moment comes as a distraught Yukio "takes responsibility" by committing seppuku with Ginji's sword. Just before she goes through with it, Revy screams, "Rock! Don't look at her! Look at me!" She cared so much for him that she tried to have him look away to keep his fragile sanity from breaking.
- The end of the first gunslinger-maid arc, when it's being outlined to Garcia what Roberta's evil past is. We're all tensed up for Garcia to cut and run in horror... and his response is to Glomp her and shout "I don't know any serial killer! She's somewhere else, far away!" Her past identity as a killer doesn't mean she's not the kind, loving maid he's always known, and the clear send-up that redemption is possible is heartwarming in spades, especially given the series' position on the Sliding Scale of Idealism vs. Cynicism. In fact, that position adds extra strength to all the moments like this in the series.
- Shortly thereafter, Garcia tells Balalaika that Roberta's his maid, and that he will see to her...and Balalaika is so pleased to see Garcia living up to the responsibility of his name and position that she orders Sgt. Borisov to see to Roberta's injuries, and get them safely to the airport..."and if the Cartel tries to interfere, deal with them as you see fit." Balalaika may be a criminal and leader of criminals, but she still remembers that she was once an honorable officer, and respects honor when she sees it in others.
- One thing that shows how twisted the morality in Black Lagoon is that one (possible) Heartwarming Moment is an adult woman threatening to kill a child. Or, to be more precise: Revy telling Gretel: "You mess with [Rock] once more, and I'll kill you." That, plus the punch in Gretel's face after Rock stormed out of the room, is the very first time she openly protected/defended him.
- And the reason that Rock stormed out of the room? He had just listened (with sadness and horror rather than disgust) to Gretel's coldly-delivered Breaking Speech, which laid bare the fact that she was so traumatized by her past of rape and torture that murder had become her and her brother's sole source of joy. He had held her in a tight embrace and wept for her, begging her to accept the possibility that there is hope, and still a possibility of a new and happy life for a little girl like her. This act of sincere kindness, so alien to Gretel, had been enough to move even a mass murderer like her to blush like a real little girl for the briefest of moments... before, in one of the saddest moments of Evil Cannot Comprehend Good ever, Gretel had offered herself sexually to Rock as a form of thanks, thinking that this was the only way an adult would appreciate her in return.
- Lotton the Wizard offering a badly wounded Shenhua a hand after the huge fight at the Lagoon warehouse, stating that he wasn't about to leave her behind to die. On the way out, they even appear to be stopping to help the traumatized Sawyer as well. Shows that even among the Roanapur Freakshow, there seems to be a bit of comradeship between ruthless bounty hunters. To add to the heartwarming, the three end up staying together and work as a team during the Roberta's Blood Trail arc!
- The end of "El Baile de la Muerte". Garcia goes up against Roberta, who is in full Ax-Crazy Implacable Man mode, and has fought the Vysotniki and a detachment of US Special Forces and come out on top and basically brings her back to herself, even knowing that she's gone mad and would shoot him, too. He cares about her that much. And he snapped her out of it...with a kiss!
- A minor one in episode 3 of Roberta's Blood Trail, when Rock, Revy, Garcia, Fabiola, and Shenhua find Roberta, all hell is breaking loose. When given the opportunity to back out, Garcia says that he owes it to Roberta to bring her home and he won't let her down. Shenhua tells him that that was well said and that he had the heart of a warrior, despite the fact that going anywhere near a pissed off Roberta is a death sentence and that Garcia's statement pretty much meant that she would be facing down Roberta.
- Gretel walking alone on a dark beach while 'The World of Midnight' plays...and then you see the beach brightly lit with Hansel and Gretel standing on the beach holding hands.
Hansel: (after gently kissing Gretel on the lips) Good luck, Sora Mea. I love you.
- The last thing Hansel and Gretel say to each other before splitting up is actually kind of sweet. It just shows that their relationship is indeed the most humanizing thing about them.
Gretel: I love you too, Fratello Meu.
- Minor, but every time Revy calls Rock "babe" or "baby" (not being snarky, but rather endearing) instead of "Rock" in the Fujiyama Gangster Paradise arc, provokes a little "Squee" of happiness from this little touch of tenderness from Revy towards Rock.
- When Caxton's troops tell him they rescued Garcia, he tells them that he would've kicked them out of the unit if they had not. Seeing that someone in the Black Lagoon world cares about innocent bystanders was surprisingly touching.
- The way Chang ends the second Lovelace job for himself, specifically trying to give Rock something resembling an ending. It's more of a gentle Breaking Speech than anything, but that sort of kick in the pants is what Rock's apparently needed since Fabiola brought him down a peg. Even though Chang's probably got several different practical reasons for doing so, and just got done laughing in our faces for thinking of him as the "decent" crime boss, it's rather nice seeing him act the Older and Wiser figure and straighten the newly-minted crook out a bit.
Heartwarming / Black Lagoon