Junji Ito/Heartwarming

Ito Junji no Neko Nikki. Although it's actually more of a funny manga, it has some heartwarming moments too. Find the manga and see by yourself; describing the moments might prompt a "I CAN'T BELIEVE IT" bit.
Smashed has Ogio's backstory reveal that he was rescued by a tribe while hiking in the Amazon, who nursed him back to health and sent him on his way with a jar of special sap. They advised him to eat it without being seen. Considering the reason why, that was good advice.
"Ghosts of Primetime" has the main character attempt to save his friend and mother from a pair of terrible comedians. They use spirit powers to attempt to tickle the three of them to death, but only get the best friend.
"Gentle Goodbye" has this and a moment of awesome for the main character Rika. She's technically not alive, finding out that she's a construct and the real Rika died after her engagement party to Makoto. Makoto begged his family to bring her back, and Rika was left in the dark about what she really was, not knowing she would fade in twenty years. To top it all off, Makoto's been cheating on her and plans to marry the other woman, revealing this fact ten years after the construct came into the world. After saying goodbye to the construct of his little sister, Rika heads home and sees her father. She spent most of her life having nightmares that he would die, and has now accepted that fate. Rika smiles at him as he looks at her transparent form with concern. She doesn't know which of them will pass first, but she has no intention of wasting that time.
Sensor has its moments:
- The stories show that a journalist is following Kyoko after she survived a mysterious eruption, while having a sudden shock of volcanic-golden hair. At first, it's to get a scoop because that's what journalists do. Then they both get captured by a cult, and when a fire breaks out, his first reaction is to save Kyoko where she's tied to a cross. He then follows her around the country, not just for the story, but to make sure that she's safe. The manga ends with Kyoko thanking him for always looking out for her, before sending him to safety.
- Father Miguel is a Nice Guy in the past. When he gets wind that the local government wants to martyr him, he says he's not afraid to die. Father Miguel is more concerned about his followers, advising them to leave him to his fate, but they should all have a chance to live.
Junji ito when he's not drawing horror is shown to be a Nice Guy. He talks fondly of his cats, and later mimics being "Spacejammed" (his words) to appear at a virtual convention.
"The Whispering Woman" while the story itself is a mix of horror and tragedy, there are some heart warming moments.
- For context. Mitsu is hired by a wealthy man to help take care of his daughter Mayumi. Mayumi suffers from a disorder in which she cannot make even the simplest decisions without obsessively questioning them. Maids whom have tried to help her in the past have resigned left and right. Mitsu on the other hand, once the situation is explained to her, is able to make sure Mayumi is able to sit down and relax after a recent panic attack. She goes the extra mile and walks with Mayumi everywhere she goes, whispering and hand signaling every instruction and always staying by her side at the expense of her own health and wellbeing. When asked why she would do this. She simply replies that it allows her to live again as her "past self". The work is so effective, Mayumi was able to formally greet her father and offer him a flower. It turns out Mitsu has a free loading boyfriend, named Aga. Who abuses and robs her on a daily basis and on top of getting more money, she uses the job to escape her life.
- One specific instance has Mitsu walking down the street with Mayumi. With her instructions, Mitsu was able to save Mayumi from being killed by a freak truck accident, simply by telling her to walk on the side opposite of where she usually walks. Mayumi's dad refers to her as a goddess or a guardian angel because of how lucky it is.
- Mayumi's final conversation with Mitsu before she gets murdered. At this point Mayumi has begun to function properly in life and feels sad because that would mean that Mitsu would no longer be needed. Mitsu comforts her. The anime "Junji Ito Maniac: Japanese Tales of The Macabre", expands on this. First Mitsu reassures Mayumi, that she will do fine on her own and that she has some good news. It's not said what it is. In the end When Mayumi kills Aga as Mitsu's final instruction we finally hear what Mitsu whispered last.

Mitsu: I will always be at your side Mayumi.