Naruto's Isolation is Nothing Compared to Chainsaw Man's Greatest Fear
Warning! Spoilers ahead for Chainsaw Man chapter 96!
As a Jinchuriki, Naruto lived a cursed life for most of his adolescence but his struggles pale in comparison to the fear that consumes Denji ever since Chainsaw Man became his heart.
The moment Naruto's parents sealed the Nine-Tails beast Kurama into him, transforming the boy into a Jinchuriki, Naruto's life changed for the worse, despite being the son of the Fourth Hokage. The villagers of the Hidden Leaf Village feared and ostracized him for containing the ostensibly strongest of the nine-tailed demons, and Naruto's classmates teased and bullied him for being a monster. Although a social pariah, Naruto never allows the disapproving eyes and harsh actions from his fellow kin to hinder his dreams of one day serving as their protector, which he eventually achieves by becoming the Seventh Hokage.
It's Naruto's unbreakable positive attitude that hides his true suffering from the reader, diminishing the overall effect that his predicament would have had on the series if he weren't so annoyingly upbeat despite the circumstances. In Chainsaw Man, however, Denji's woes and fears are much more prominent. After getting cut into pieces, Denji's true anguish begins when his devil friend Pochita brings him back to life by becoming his heart, transforming Denji into Chainsaw Man.
In chapter 36, Denji goes into a downward spiral when Katana Man accuses him of being the only one of them who doesn't have a human heart. These words are especially meaningful as Samurai Sword is a devil-human hybrid. Ever since that pivotal moment, Denji struggles with his identity, wondering if Samurai Sword was right. Later on, Denji's fears are realized when he fails to react to bad movies in the same way as other people in a local theater and expresses his concern to his date, Makima. Unfortunately, his uneasiness about his lost humanity is confirmed every time a devil attacks him with the intent of stealing his heart. Demons wouldn't want a human heart, they want Pochita. There's also a concerning moment earlier on when Denji doesn't feel anything after a fellow comrade dies while others are left in tears, fueling his fears.
Although Chainsaw Man's suffering is more acute than Naruto's, both characters' experiences are saturated in irony. In Naruto's case, even though the people of the Hidden Leaf Village treated him with contempt, Naruto still wants to prove to them that he is worthy enough to be their Hokage, which is a fervent demonstration of strong moral fiber and humility. For Denji, he's so focused on his inability to experience sadness or grief that he doesn't realize he's passionate and loyal to a fault, which are signature human emotions. Naruto's is once again more positive, as it just further underscores his purity and ability to forgive while Chainsaw Man's is less flattering and even heartbreakingly naïve.
But all of this changes with the death of many of Chainsaw Man's friends near the end of the first part of the series, causing Denji to fall into a deep depression. He can't even taste meals, the consumption of which has always been incredibly important to him as one of his life's goals when he lived in destitution was to eat food that wasn't rotten. The fact that Denji gets depressed might be why he later refers to the removal of Pochita from his body as removing him from his heart. This is crucial as Denji has always obsessed over his heart as being the gateway to human emotions, proving he may have finally moved past his fear. Regardless, Denji's suffering as Chainsaw Man is undeniable and more debilitating than Naruto's.