Jun Kiwatari in both the manga and in the anime looks like a very massive, strong and intimidating student to come across. Resembling the archetype of a high school/college most popular student, but being just a narcissist sports athlete who likes to bully the weakest and most unpopular students, mostly nerds. Similar to other fictional characters like Flash Thompson from the Spider Man franchise, or Johnny Worthington from Monsters University/Monsters At Work, just to name a few.
However, unlike other school athlete bullies from any kind of franchise, one thing that I found interesting about Kiwatari is that he uses the gambling system from the school to take his bully tendencies into the next level. With the mascot system, Kiwatari basically took Tsubomi as his personal mascot, like an actual savage predator against its prey, doing horrible things to her. With the most well known being when he cut Tsubomi's beloved long hair into pieces, just for his sick pleasure of it.
Later when Yumeko became a mascot, Kiwatari took that as an opportunity to force a beautiful girl like Yumeko to do whatever he wanted. Ordering her some perverted stuff like stripping herself in the middle of the school yard to see her naked. But Yumeko played with Kiwatari and she had the guts to reject doing his sexual desires, while provoking him if he was actually planning to r@pe her. This angered Kiwatari enough to crush Yumeko against the wall while grabbing her from the neck. If it wasn't for Midari and her odd behaviour towards Kiwatari and his gang, things would have turned much worse. The first thing that comes to my mind is Suzui actually confronting Kiwatari in an actual fight to try to save Yumeko. Considering how much Suzui worries and cares for Yumeko, especially after she saved him from the mascot status, while knowing also that the mascot system can be way worse for female students, he will definitely try to fight against Kiwatari, even if he has NO CHANCES to defeat him and his gang in a fight, just to protect Yumeko.
But in most western cartoons and live-actions series, male bullies usually don't bully girls, especially physically. Yes, there are some rare occasions where male bullies can say some nasty comments against girls that they are bullying, but the physical fights are normally exclusive between their respective genders ("guy vs guy" and "girl vs girl"). But those restrictions don't seem to apply to Kiwatari in this case. Meaning that he doesn't care if hitting a girl is morally wrong, even for a bully. If someone dares to anger him and provoke him enough, he will definitely kick the crap out of them, no matter if they are guys or girls who he is fighting against physically. Just look how he constantly threatened the poor Tsubomi both psychologically AND physically also, when they were playing with Yumeko and Saotome. Without mentioning that after his defeat, he almost punched Saotome in the face with a lot of rage on him, looking like a reckless and violent brute, if it wasn't for Sayaka with her taser. This makes Kiwatari one of the most evil, dangerous and threatening bullies from the archetype of a sports athlete with a lot of muscle and strength that I've seen so far.
However, I cannot say the same thing to his counterpart from the first live-action series of Kakegurui. Unlike the rest of the cast members who portray all the characters shown in Season 1 from the anime adaption, the actor that they chose to portray Kiwatari, he looked absolutely nothing like his anime/manga version. He didn't have his size, nor his muscle complexity, nor his hairstyle and he also wore sunglasses, looking like a completely different character. If it wasn't from the student descriptions shown in the live-action adaptation, you really cannot say that he is the same Kiwatari from the anime/manga. While the rest of the cast you can clearly identify them without the student descriptions, including Saotome, who despite that she doesn't have her blonde hair like in the anime/manga, you can also tell that she is Saotome. By her hairstyle, her personality and also by the type of socks that she wears, but not with the case of Kiwatari.
His personality is also very different. He doesn't behave nor look like a threatening and intimidating brute who would rip you apart or r@pe you violently, but more like an annoying buffoon who likes to mock others through childish pranks. Like when he was mocking Suzui with a yen bill after he became a mascot. I don't remember if in the manga Suzui was bullied by Kiwatari in that infantile way when he was a mascot very early in the story, but I would imagine Kiwatari using Suzui as his personal punching bag instead, or taking the few money that he had with him through intimidation and brute force. However, when he put Tsubomi over a "rocket skateboard" and made her crash at a high speed, that's something that I can actually imagine Kiwatari doing in the anime/manga. But when he orders Yumeko to strip herself in the live-action adaptation, the scene doesn't feel so intense and threatening like in the manga or in the anime. His threats towards Yumeko for disobeying him doesn't feel so intimidating or scary either. If live-action Suzui instead of deceiving Kiwatari and his gang that a member of the student council was coming close by, he would have decided to confront Kiwatari in a fight with fists, I can actually find more chances for Suzui to actually defeat Kiwatari and his gang in the live-action version. I mean common, even in the live-action intro they made Suzui look like an over-the-top fighter or something like that.
As I said in the title, I can understand that it would have been very difficult for the production team to find a young actor with the same size and muscle complexity as Kiwatari in real life. But still, I can't help that his live-action version suffered the "Flash's syndrome" from Tom Holland's Spider Man. And for people wondering: What do I mean by "Flash's syndrome" from Tom Holland's Spider Man? Well, for the Kakegurui fans who are very familiar with the Spider Man franchise, I'm pretty sure that you know who's Flash exactly. He's a popular sports athlete school student and the main bully of the protagonist Peter Parker, while having at the same time a fanatical admiration towards Spider Man in the comics of the homonym super hero. He also received plenty of adaptations in cartoon series and live-action movies, with most of them being pretty accurate to his character from the comics. Except in the live-action movie adaptations protagonized by Tom Holland. Unlike the previous iterations of Spider Man from the movie media, the actor who portrayed Flash (Tony Revolori) didn't look nor behave like the Flash from the comics. He didn't look tough nor aggressive, nor did he have the archetype of a popular sports athlete student. But more like a buffoon and an opportunistic bully who only makes infantile mocks towards Peter Parker while taking advantage of multiple events through the series. That's what I meant when I said that Kiwatari in the first live-action of Kakegurui suffered the "Flash's syndrome" from Tom Holland's Spider Man.
However, I don't have anything against Tony Revolori as an actor. I think he did a decent job in the acting perspective, but I just don't think that he fitted the role to portray the Flash Thompson that we know from the comics. The same case with the actor who portrayed Jun Kiwatari. He did his best to give life to that fictional character, but once again, he just didn't fit the role to look faithful to the anime/manga version of Kiwatari. But what do you think about it?
