No person is exactly like another. Each individual has his or her idiosyncrasies, likes, dislikes, and personality traits. Because of this, it becomes difficult to form bonds and understand one another. This inability to get along is especially evident in the relationships between protagonists and antagonists in media. The inevitable clash between foes occurs because the hero and villain have vastly different motivations.
However, heroes may not truly grasp what they are opposing. Likewise, heroes may misunderstand their supposed nemeses. Villains are often only villains because they stand in the hero's way, but underneath, they may be likable and just people. Sympathetic villains are a staple in anime, and often, these villains are future friends.
WARNING: The following contains spoilers.
10 Izuriha Overcomes Her Envy And Conversion Disorder Because of Mato's Persistence (Black Rock Shooter)
Mato Kuroi befriends Yomi over their shared love of a book. As a result, Yomi introduces Mato to another friend of hers named Izuriha Kagari. Izuriha immediately becomes hostile, believing that Mato is trying to replace her as Yomi's friend. As a child, a car hit Izuriha while she chased after the car of Yomi's family. Izuriha, now bound to a wheelchair, holds her accident over Yomi's head and demands Yomi to do whatever she wants in order to "take responsibility." While Izuriha and Mato argue in reality, manifestations of their mental states known as "otherselves" battle in another realm. Upon Izuriha's defeat, Mato breaks through to her and slowly becomes Izuriha's friend. Izuriha overcomes her conversion disorder, a disability caused by a mental disorder rather than physical symptoms, and begins to attend school with her friends.
9 Raji Repents & Works To Be A Better Person Because of Shirayuki's Friendship (Snow White With The Red Hair)
Prince Raji of Tanbarun is undeniably a villain at first. He desires to have Shirayuki as a concubine due to her unusual hair color. Shirayuki retreats to the neighboring kingdom of Clarines, and Raji uses force and poisoned apples to bring her back. He relents after Prince Zen of Clarines defends Shirayuki. She tells Raji that she wants him to become a prince who will make Tanbarun proud. He takes her words to heart and later invites her back to the kingdom. Raji apologizes, and the two become friends. What starts as a misogynistic obsession changes into friendship and genuine love on his part.
8 Seth And Hameline Bond Over Their Similar Childhoods & Defend Each Other (Radiant)
One day in The Pharénos, creatures called Nemesis fall from the sky. They possess a form of magic called Fantasia, and any human who manages to survive a Nemesis's attack obtains Fantasia. Seth lives through a Nemesis invasion and becomes a sorcerer, growing horns on his head because of this so-called "infection." Humans, terrified of sorcerers, form The Inquisition to hunt them down.
As a teenager, Seth battles a girl named Hameline who uses her mice Nemesis to terrorize the town that imprisoned and hurt her. Realizing Seth has also lived through abuse, Hameline surrenders and becomes his friend. When The Inquisition arrives to apprehend them, Hameline sacrifices herself so Seth can escape. He goes berserk in grief and drives away The Inquisition. In the aftermath, Seth adopts Hameline's mice in her memory.
7 Ichigo Learns To Understand Quiche, And He Grows To Love Her (Tokyo Mew Mew)
Ichigo's mission as a magical girl is to defeat the aliens trying to take over Earth. Quiche is the first alien she encounters, and with his desire to destroy humans, the two become enemies. Throughout their battles, Quiche develops feelings for Ichigo. Later in the series, Ichigo discovers that the aliens inhabited Earth before humans. They left the planet when the environment became toxic and wished to return. She accepts Quiche and his people but continues to defend humanity. In the final battle, Quiche defies his ruler and takes a blow meant for Ichigo. He reaffirms his love for her and dies in her arms. Ichigo mourns his death and fights with renewed purpose.
6 The Hand Demon Respects Tanjiro, And Tanjiro Empathizes With Him (Demon Slayer: Kimetsu No Yaiba)
Tanjiro of Demon Slayer is one of the kindest protagonists in anime. A great example is when Tanjiro fights the Hand Demon during the Final Selection trial. The Hand Demon is vindictive and consumes multitudes of would-be demon slayers. Because of his grudge against Sakonji Urokodaki, the man who trapped him, the Hand Demon swears to eat all of Urokodaki's students. Tanjiro becomes enraged after the demon gloats about devouring his fellow trainees and vanquishes the Hand Demon once and for all. However, as Tanjiro learns of the demon's past, he holds the demon's hand and prays for the demon. Touched, the Hand Demon cries and appreciates Tanjiro's kindness.
5 Haru And Shuda Become Brothers (Rave Master)
Haru Glory's first major struggle is against Shuda of Demon Card. He defeats Shuda, but the platform underneath them begins to collapse. Shuda refuses Haru's outstretched hand and seemingly kills himself. While mangled and scarred, Shuda survives and meets with Haru's father Gale, promising to protect Gale's children in the event of his death. Gale dies saving Haru later in the series, and Shuda reappears to join Haru's team.
Haru discovers from a crystal that reveals memories that Shuda approached his sister Cattleya to inform her of her father's death. While visiting her, the two form an intimate relationship much to Haru's disgust. Shuda shyly jokes that Haru could call him "brother-in-law," and the two eventually do become family.
4 Tsuna And Mukuro Accept Their Differences And Join Forces (Katekyo Hitman Reborn!)
Wanting to prove his strength, Mukuro makes a list of the toughest students in the district and systematically defeats them. After Mukuro injures his friend, Tsuna challenges Mukuro to defend other students. Tsuna wins and earns Mukuro's respect. Mukuro reveals that he was an experiment as a child. Scientists tortured him by killing and resuscitating him in a never-ending cycle to see if he developed superhuman abilities. Tsuna empathizes but does not forgive him, and Mukuro becomes one of Tsuna's guardians in the next arc.
3 Tohru Forgives Akito, And They Become Friends (Fruits Basket)
Fruits Basket fans struggle with Akito as a character. From her introduction, Akito demonstrates her cruelty and solidifies herself as a villain. She psychologically tortures Yuki, abuses multiple characters, and manipulates the Sohma family without remorse. However, Akito herself is just another victim corrupted and broken by her mother. While that does not excuse her behavior, saintly Tohru still accepts Akito despite her crimes and offers to be her friend. Tohru understands Akito's fear of loneliness, and Akito breaks down from Tohru's kindness. The two remain friends throughout their lives.
2 Natsu And Gajeel Become Guildmates and Friendly Rivals (Fairy Tail)
At the beginning of the Phantom Lord arc in Fairy Tail, Gajeel trashes Fairy Tail's guild hall and strings up Team Shadow Gear crucifixion style, leaving the Phantom Lord logo on Levy's stomach. Natsu beats some sense into Gajeel, and the two grow to respect each other as fellow Dragon Slayers and become rivals afterward. Gajeel apologizes and works to gain the trust of his guildmates once he joins Fairy Tail. He reveals himself to be just as dorky as the other members, contrary to his first appearance. The culmination of Gajeel's growth is shown during his fight alongside Natsu against Sabertooth, and Gajeel proves himself a true mage of Fairy Tail.
1 Naruto And Nagato Share A Master And A Dream (Naruto)
Jiraiya's death at the hands of Pain devastates Naruto. So when Pain destroys Konoha in search of him, Naruto fights to avenge his master and village, rather than protect himself. After defeating all Sixth Paths, Naruto confronts the "true Pain," Nagato. Naruto listens to Nagato's story about war and life as Jiraiya's student and vows to achieve the peace that Nagato desires. Satisfied, Nagato entrusts his dream to his "sibling student" and gives up his life to revive those who've died during the attack on Konoha. Naruto remembers Nagato as a brother, not a villain.