Nice Guy / Demon Slayer: Kimetsu no Yaiba

• Tanjiro is characterized by his kindness and loyalty. He has an endless reserve of compassion for everyone but the vilest of people. If asked for help, regardless of the task, he will work his hardest to see it through.
• Tanjiro's sister Nezuko, even if she's been turned into a demon, still carries the compassion and love that she had as a human. And after gaining resistance to the sun and starting to speak again, she becomes closer to becoming the kind young girl that she was before.
• Don't let Zenitsu's apparent cowardly antics fool you, he is actually just as much of a nice guy as the ever selfless Tanjiro is; Zenitsu has gone on record of being nice to people he had only met for minutes at most, and being good to people he actually knew didn't even like him because Zenitsu just wanted things to be better, and even Inosuke whom he is always butting heads with, Zenitsu tried to cheer him up along with Tanjiro after the Spider Family fight left Inosuke feeling he was weak and useless.
• Besides being one of the two Big Goods, Demon Slayer Corps' leader, Kagaya Ubuyashiki, is one of the kindest men alive. He refuses to treat Nezuko as a monster, is kind to Tanjiro, and loves every member of the Demon Slayer Corps like his own children.
• Murata is a very kind and friendly young man and easily befriends Tanjiro and the other heroes. He even compliments Tanjiro's cooking skills during their training with Himejima and shows great concern and care for an injured Zenitsu.
• Tamayo is one of the very few good demons in the series, to the point that she dedicates her life to creating an antidote to turn demons back into humans.
• Mitsuri, the Love Hashira is one of the nicest characters in the entire series and clearly the kindest of the Hashira. She is the only one of them who didn't want to kill Nezuko immediately upon meeting her. In fact, she's the only Hashira who interacts much with Nezuko at all.
• Flame Hashira Kyojuro Rengoku. Despite initially wanting Tanjiro to be punished for traveling with a demon, he quickly warms up to the Kamado siblings during the Infinity Train arc, and says that Nezuko, by fighting to protect humans, is part of the Demon Slayer Corps.
• Giyu Tomioka took the unprecedented step of sparing Nezuko despite her being a demon, recommended Tanjiro to Urokodaki for training, and guaranteed the Kamado sibling's life by promising to commit seppuku with Urokodaki should Nezuko attack or kill a human. Giyu later shows more of his nice side once Tanjiro's words convince him to let go of his guilt for losing Tsutako and Sabito; he smiles more and actually thinks about trying to get along with Sanemi by giving him his favorite food, ohagi. Had he let his prejudices rule him over his innate nobility and idealism, we may never have this story to begin with.
• Despite her constant anger, Shinobu is willing to listen to Tanjiro's story about Nezuko and entrusting to him her dream of befriending demons. She later shows kindness showing her pet goldfish to a curious Nezuko and praising Tamayo for her work despite her innate hatred towards demons.
• According to Shinobu, her sister Kanae is exactly like Tanjiro personality-wise, to the point where she believes that there are good demons out there.
• Gyomei Himejima, despite his tall, stoic, and intimidating appearance, is a kind, gentle, and soft-spoken man, always being kind and polite towards others. He even accepted Genya as his disciple, despite learning that he eats demons to make up for his lack of Breathing skills.
• Goto is a very docile and gentle individual. He has a deep respect for Tanjiro, Nezuko, Zenitsu, and Inosuke because of their bravery and capability. He even visits Tanjiro after the swordsmith incident to check on his condition and his progress. He also shows concern and relief after hearing that Nezuko can walk in sunlight and speak words again.
• Kotoha, Inosuke's mother, was a gentle young mother who loved her son very much. She even showed respect for Doma for saving her and her son and always sang for him, up until she found out about his true colors.
• Yoriichi Tsugikuni was not just an unbelievable warrior, but a kind, generous and warm man. Chapter 177 reveals that he was always a very sweet person since childhood. He loved his family very much and did not object to his father's treatment of him. He felt bad for his father's retainer, Ito, after using his special talent and injuring him in his sword training. He also helped his ill mother by walking alongside her and supporting her left side, when she could not walk on her own. He treasured the flute that Michikatsu made for him, telling him that he would always remember his big brother after he prepared to travel to a temple. He didn't even stay at the temple and left on his own journey so that his brother would become the next successor to their family.
• The courtesan Koinatsu from the Red Light District Arc. She is incredibly kind to everyone around her, particularly her assistants. She also treats Tanjiro very well despite immediately seeing through his disguise.
• Keizo, Hakuji's mentor, is a very friendly man who cares for the well being of people. He even allows Hakuji to become his student despite knowing that he's a banished criminal from Edo and let him take care of his ill daughter Koyuki.
• Koyuki is a very sweet and kindhearted young girl who became Hakuji's best friend and eventually, his lover.

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