Jun Kiwatari is a minor antagonist in Kakegurui.
Jun is very tall and muscled tanned-skin man with short dark brown hair with sideboards and black colored eyes. He wears the Hyakkaou Private Academy issue uniform that consists of a red blazer with black trim that lines the cuffs and collar and has gold buttons for decoration. He wears a white button-up shirt underneath with the top unbuttoned as well as a pair of gray-black colored school jeans with and brown loafers.
After becoming a housepet, Jun was shown to have gone through major physical changes, likely due to the stress of his new situation and the harassment and abuse he now has to endure. This is seen where Jun's has noticeably lost his original muscular figure and now look emaciated, with disheveled hair and black bags under his eyes.
Jun is portrayed as a typical bully as he is aggressive, arrogant, and sadistic. He specifically targets housepets and sometimes purposefully destroys what's dear to them (like in Nanami's case by cutting her long hair). He doesn't care about anyone else besides himself. When he himself is losing, he quickly resorts to violence. Jun wouldn't even have refrained from raping Yumeko. He also shows the bare minimum of respect to the Student Council or other people. He dislikes people speaking up against him and wants to make them subordinate to him.
He often targeted new housepets and tormented them in order to break them, so he could use them for his own benefit later. When Nanami became a housepet, he escorted her out and cut her hair, even though she begged him not to. Jun compared it to cutting one's nails if they get to long and how it feels so good. Jun also bullies Ryota frequently, while he was a housepet.
Kakegurui - Compulsive Gambler
When Yumeko first became a housepet, he and his friends meet her in the hallway escorted her outside and told her to strip. Ryota Suzui attempted to interfere, but was stopped by them. When Yumeko refused, even saying he is not her type, he got violent, threatening to rape her, but Midari Ikishima came and stopped him. She offered him to be able to "do it" with her if he played a sort of Russian Roulette with her, meaning she would shoot at him once with only one bullet in the chamber. Jun got freaked out by her and left, calling Midari crazy and a "boner-killer".
During the dept-swap game, he got paired up with Yumeko and Mary Saotome. Even though he wasn't actually a housepet, he gave a friend of his some money and then wrote down a fake debt. That way he was hoping to earn a free buck and could even ruin another housepet even more. When he received the pairings, he made out a sign with Nanami Tsubomi, to show each other what card they had. He was confident and cocky during the entire game and stated how betting to little would just be boring. But when Yumeko pointed out his cheat, the plan backfired as Yumeko motivated Nanami not to listen to Jun. He got really angry and attacked her but, Sayaka told him to refrain. He swore that Nanami will regret it after the game.
In the end, Nanami ditched him and he lost. He thought it wouldn't be that bad, but Yumeko and Mary had swapped out their debt-boards, meaning his current debt he received was way higher. Thus he became a housepet. He tried to differ with Sayaka and argued that the council would only lose from that. He got extremely mad at Mary and tried to attack her. Luckily, Sayaka Igarashi stunned him with a taser, since she already mentioned that violence was forbidden. He was then left unconscious on the floor.
During his time as a housepet, he has suffered a lot and appears extremely malnourished. It has changed him forever and he seems to be somewhat traumatized. During the election, he somehow managed to gather 35 votes, which he sold to Sayaka for 280 million Yen. He uses them to buy himself free of his rank. Jun also said to himself, that he never wants to gamble again. Sayaka was impressed that someone even gambled with him in the first place. He revealed that he got the votes from Yumeko, who was obviously eager to gamble with anyone.
Jun makes a cameo in the fifth volume, where he gambles at Mary's den. After losing to Ren Kochi, he believes he was cheated and is very upset. He then yells at Tsuzura Hanatemari and accuses her of not being a good dealer. However, when Sachiko Juraku enters, he's quickly silenced by her, as she frightens him.
Jun is played by Yuuma Yamoto in the live action. His design is slightly different: he wears glasses with pink lenses, rings and a bracelet on his left wrist. He also has an earring on his left ear.
Compared to his manga counterpart, he is less serious, but maintains his abusive behavior toward housepets. He appears in almost every episode before his defeat at Indian Poker and is often shown bullying Nanami in various ways with his friends. Like in the manga, he beats Ryota up and makes fun of him. When Mary becomes a housepet, he is extremely happy and can't wait to degrade her. In a scene, he forces Nanami to greet her, telling Mary they should be friends since they're both Mittens. Both girls feel humiliated. He also appears in the live action movie. After the poker match and becoming a housepet, he joins Jueri and Amane's group Village. He supposedly bettered himself and now fights for the rights of housepets. Although that might just be a temporary scheme of his to save himself.