Both Chainsaw Man and Jujutsu Kaisen have maintained a positive level of reception from fans both manga and anime, with both of them offering similar story plots and characters. While Chainsaw Man is centered around 'Devils' throughout with some of them taking over human corpses known as 'Fiends', Jujutsu Kaisen is very alike in the aspect of 'Cursed Spirits' that stem from human emotion.
Along with this, the two main characters between both stories also tend to portray the same characteristics in certain areas, and this is what allows both Chainsaw Man and Jujutsu Kaisen to be elevated to the level that they are today.
Warning: Some Manga Spoilers
5 Wild
Given both stories' worlds, characters, and mature themes set throughout, both Denji and Yuji contain very wild and energetic traits, to say the least. Both characters contain more powerful beings within them, as Denji is one with the 'Chainsaw Devil' Pochita, and Yuji has one of the strongest 'cursed spirits' residing within known as Sukuna. While it is more of Denji's human nature to contain such a level of savagery, Pochita and the hybrid chainsaw form takes this to an entire new level.
For the most part, Yuji displays a friendly and kind-hearted nature, especially in sequences that are far more light-hearted. However, when his anger or rage begins to build, his wild nature is clear to see which is the case in his first fight with Mahito in season 1, episode 12. It is most certainly subjective as to which of these two characters is more ferocious with most fans more likely to side with Denji, but without a doubt, both share the same trait here.
4 Carefree
One of the more lovable traits between the pair is their carefree nature in certain aspects, which often showcase more of their airhead moments. Despite the clear difference in levels of affection and care between the two, with Yuji showing more care for humanity and holding stronger values and Denji showing no care for saving civilians, they both share carefree characteristics amid social interactions and friendly encounters, which offer some of the more funny moments.
In the more critical situations, both characters sometimes evoke a laid-back and comfortable nature, which some may even link to the pair being crazy given the number of things they have seen and experienced. While both stories are still ongoing and there are still more character details and traits to be fleshed out, as of now, it is safe to say that they are on par in this region.
3 Comedic
One of if not the biggest similarities between Denji and Yuji is their comedic nature and their activity of turning serious situations into hilarious ones. This is prominent in the Eternity Devil arc when Denji and fellow Devil Hunters are stuck in a hotel, and when they must find and discover a way out, Denji decides to take a long nap in the midst of a life-or-death encounter.
The comedy of Chainsaw Man shines through to its fans especially when Denji is paired up with Power, and their silly antics. As for Yuji, he uses his dire circumstances as comedic relief and is always displayed with a cheerful and hilarious level of energy whenever he is around his counterparts, especially Gojo.
2 Insouciant About Themselves
After witnessing his friends in danger at the hands of a 'Cursed Spirit', Yuji took it upon himself to go toe-to-toe with it, ultimately ending up eating one of Sukuna's fingers putting his own life at risk. As a result of this, it would mean that Yuji will eventually die along with the curse after absorbing all of the fingers, and declares that he does not care what happens afterward. This is what enables his heroic intentions as he is willing to put himself in danger for the safety of others.
In Chainsaw Man, due to his traumatic childhood and experiences, Denji does not take himself seriously at all. While there are definitely aspirations that he maintains despite how unserious they may be, he displays a nonchalant and unbothered attitude when faced with dangerous Devils and threats.
1 Passionate About Women
As many fans will know, Denji's primary focus in the story is on women and the opportunity for any sexual or romantic encounter. His sights are set on getting closer to Makima and accepts her request of eliminating the 'Gun Devil' in order for him to do whatever he wishes with her. The level of rage and brutality he takes into combat at the prospect of engaging with Power showcases the level of motivation that is stemmed from women for Denji, and it has an everlasting presence in the story. He even goes to the lengths of attempting to maintain a romantic engagement with Reze the 'Bomb Devil' after an attempted assassination.
Yuji, while nowhere nearly as fixated on women in Jujutsu Kaisen compared to Denji, still declares his taste and preferences when it comes down to it which is what forms the relationship between him and Aoi Todo. The description of a 'tall woman with a big ass like Jennifer Lawrence' rings clear to showcase his passion for women similar to Denji.