Toshiki Kai is the deuteragonist in the Cardfight!! Vanguard (V Series Anime), and has recently enrolled as a first year at Hitsue High School since he moved back to his home town. He seeks to gain true strength when it comes cardfighting. His Vanguard Circle is red.
Despite being continuously referenced as 'Kai' both in-series and out, Kai's given name is in fact Toshiki. Going with Japanese rules of etiquette, none of the characters in Vanguard refer to Kai by his given name because none of them are close enough to him socially to speak to him as such. Even his best friend Taishi Miwa likely calls Kai by his surname due to them respecting one another.
His family name, Kai (櫂) means paddle; oar; scull.
Kai is a serious person and doesn't like to joke around like other people his age. He doesn't talk much or to anyone. When cardfighting, he is shown to be more serious and confident on winning the game without any need of support. Despite his selectively mute personality, he has a best friend, who is Miwa. However, after his cardfight with Aichi, he is more social and nicer than his original series counterpart.
In the V Series, he seems a bit more upbeat and can get focused to the point he forgets his surroundings like when he and Koutei both completely forgot about the Shop VS Shop Tournament. He worries about his actions like when he left Ren and Tetsu as well as telling Aichi to give up Vanguard.
After his fight with Ibuki, he had lost the drive to play Vanguard much like everyone who fought Ibuki and had no desire to return to it in spite of his efforts during the climax of the battle between Cray and Brandt. It would be thanks to Mamoru Anjou and his battles during the Vanguard Kousen that would get him back into the swing of things and resume loving Vanguard.
In Cardfight!! Vanguard Extra Story -IF-, it is revealed that due to Shuka taking Blaster Blade from Kai before he gave it to Aichi, he would have lived a totally different life than that of the original timeline. In this version, he was very lighthearted and socialable, seemingly happier than he was before.
Kai is normally seen wearing his Hitsue High School uniform, which consists of a blue jacket and pants with white trim, and a white dress shirt. His uniform, however, seems a bit worn out. His casual attire consists of a tan, zip-up, long-sleeve shirt, with a maroon jacket with black accents, grey jeans, and dark grey boots.
In -IF-, he now wears a white sweater with a red jacket, while also retaining the jeans and boots.
Long before the start of the events of the anime, Kai was a typical kid who loved playing Vanguard. He would often play with his best friend Miwa. During this time, he also met Aichi and offered to teach him how to play Vanguard, giving him Blaster Blade as a gift in hopes of being able to battle him one day soon. Shortly after this however, his parents would steal money from the company they worked at, leaving Kai by himself. Because of this, he was passed on from one family member to the next. Despite being family, most of his family saw him as a nuisance because of his parent's actions and wanted nothing to do with him. Kai resented his family because of this, believing that they were all just liars and wanted nothing to do with them. He would strike out on his own often, playing Vanguard at the local card shops with his friends. His skills got to a point though where he would win everytime, something the people around him did not take lightly and refused to battle someone they felt they would lose to. Eventually Kai would find other players and best them, earnign the nickname Solitary Fighter. It isn't until he meets Ren Suzumagori and Tetsu Shinjou where he finally found people who could accept him in spite of his great strength. Little did he know however that his actions would shape Ren's idea of the world where only the strong survive and eventually awaken to a mysterious power. Ren's thrist for victory soon outweighed his desire to have serious battles with others and this upset Kai. Unable to stand the new Ren, he left Team Foo Fighters.
He would then be given a sort of trust fund by one of his relatives, stating that he would have enough money to enroll in high school and college should he allocate his funds properly and was told to decide his own future. With this, he chose to go back to his hometown, leaving Ren and Tetsu behind, causing Ren great strife and warped his ideals even more.
He would later reunite with Miwa, attending the same high school, and talk about how big they were into Vanguard still. Kai tried to be aloof with Miwa, but his constant jabs eventually wore Kai down. Miwa then showed him to his favorite hang out spot, Card Capital, mostly because of the store clerk Misaki. Once there, they happened upon Morikawa and his friends battling someone and witnessed Morikawa win with ease. This prompted Miwa to suggest that he battle Kai to see who the best fighter was. Kai battled and defeated Morikawa easliy, commenting on how it wasn't a serious battle. Kai and Miwa would later return to Card Capital and battle Morikawa once again, with him using his newly aquired Blaster Blade card he stole from Aichi. Kai would not battle him, so Miwa offered to do battle in exchange for the card if he won. Morikawa thought Miwa beneth him and lost. Miwa obtained Blaster Blade just as Aichi entered the store and asked for his card back. Kai then told Aichi that Blaster Blade had been lost to him in his fight and the only way he could get it back was if he battled for it. Aichi accepted this and the first fight between Kai and Aichi began.
Before the fight, Kai returned Blaster Blade, telling Aichi that he needed it to complete his deck and that it would be enough of a handicap for him. Kai explained the rules to Aichi as they played. Kai had Aichi on the edge, especially when Aichi was unable to ride his Vanguard to Grade 2, but in the eleventh hour, Aichi managed to ride Blaster Blade and used it to defeat Kai in a stunning turnaround. Kai was impressed and told Aichi to keep Blaster Blade. The next day, Kai returned to Card Capital, offering Aichi a chance to battle him to which Aichi agreed to happily.
Every day was pretty much the same for Kai after that. He, Miwa, and Aichi would play against one another at Card Capital. This continued until Kamui Katsuragi appeared, challenging the best player in Card Capital. Kai had elected Aichi to face off against him and thus began their match. While Aichi did struggle mid-fight, Kai continued to believe in his potential, stating that his imagination would get stronger with every fight, witnessing Aichi ride his new Ace, Alfred Early, and defeating Kamui. He was there when Aichi asked Misaki to battle him since they were both beginners and it would be something new for them. Despite the odds, with Misaki's edetic memory, she pulled off the win. Kai shows great pleasure in Aichi's progress, believing this loss to be a good learning experience.
Eventually Kai learns that Kamui and Aichi have gone and created a Shop VS Shop tournament against the card shop Voyage, which is boasting a powerful team with the top three Vanguard Fighters in Asia, those being Gouki and Nagisa Daimounji, Kenji Mitsusada, and Leon Soryu. Kai was tempted to fight in this so long as Kamui and Aichi were part of the tournament since they started it and they recruited Misaki as well. Shin named the newly formed team after the Italian word for Four-leaf clover, Team Quadrifoglio (Team Q4 for short).
Kai battled against Kenji Mitsuada and his Dimension Police deck. During the battle, Kai noticed that Kenji's style involved protecting his rearguards and tried to eliminate as many as possible. This proved to be fruitless as Kenji managed to overwhelm him with his superior tactics and power. Kai, not backing down, still manages to pull a victory over him, helping Card Capital win it's second match. To the shock of everyone, both Kai and Kenji were so absorbed in the game that they forgot about the Shop VS Shop tournament.
Sometime after the tournament, a member of Team Foo Fighters arrived and started hassling the customers of Card Capital, forcing the players to wear the VF Gloves designed to 'enhance' concentration and 'stimulate' their minds. Kamui had explained the real reason he wanted to get better was to someday put them in their place for ruining Vanguard for his friends and the shop he used to frequent. The fighter, Minami Kawanami, forced Morikawa to fight with the gloves and caused him great pain with each damage check he had to do. Kai, having enough of the tormenting, decided to challenge Minami to a battle. Kai's ferocity and imagination were simply too much for Minami as he and his crew ran off before the final damage check, noting that Team Foo Fighters were always cowards who couldn't hold to their own creed in tough times. He then looked to Kamui and told him to not get involved with them ever again and left.
Kai was then approached by Tetsu Shinjou and challenged to a card battle. Tetsu went on to explain why Team Foo Fighters was going around card shops forcing people to battle with the VF gloves. He explained that it was to help stave off Ren's bordem as he found no challenge anywhere. He also mentions that Ren has perfected PSYQualia and will continue to conquer the world of Vanguard. Kai dismisses Tetsu's ramblings and leaves. Later, Kai reminises about his team at Ren's side, coming to the decision that he needs to stop Ren's ambitions before he ruins Vanguard for more people. Miwa joins his cause and together they head for Team Foo Fighter's base of operations where they proceed to decimate every fighter sent against them, including Asuka. Tetsu had invited him to wait for Ren's return and have their decisive battle.
Once Ren arrived with Aichi and learned that he has PSYQualia, he demands that Aichi throw away his cards and swear off Vanguard. Aichi, however, refused to go back to how he was before Vanguard and defied Kai's request. This upset him but also made Ren's case that much worse as he learned Aichi defeated Kai and was fixated on having a match with him to rectify the situation despite Tetsu's pleas to ignore Aichi. He manages to get Ren's attention by offering him a chance to surpass him by battling him to which he agrees to. Despite Kai's amazing plays, he is unable to surpass PSYQualia and loses to Ren, causing him to pass out in exhaustion after fighting with the VF Gloves. Ren then focuses on fighting Aichi in order to say that he's truly surpassed Kai and become the ultimate fighter. Kai pleads with Aichi to not fight Ren and to forsake the world they inhabit, but Aichi decides to battle with Ren at Miwa's request to end their suffering, both Kai's and Ren's, and is thrusted onto a couch to relax as Aichi and Ren begin their battle. To the shock of everyone, Aichi surpasses Ren's image of victory and summons Exculpate the Blaster and then resummons Blaster Blade to defeat Ren and end his reign.
The next day, Kai skips out on school to work on his Deck, wanting to improve it so he could fight better against anyone. Miwa vists him, letting him know that Aichi stayed home from school due to being sick. He felt guilty about telling Aichi to throw away his cards and quit Vanguard with Miwa tells him that Aichi knows that he said that with his best interests in mind and points out that for Aichi and Ren, he is their Vanguard, someone lighting the way for them. He contemplates this and finishes adjusting his deck. Miwa offers to practice against him and they do so all night.
The following day, Kai challenges Aichi to a battle with their relationship coming full circle: they fought as friends, as mentor and student, and now they arrived as rivals, equals in the game they love. Kai reflects on his life and what lead him to be where he is today, commenting that the reason he gained strength was to find a place for himself in spite of his life. He then asks why he enjoyed his first fight with Aichi after so long despite losing and he figures the reason is due to having a serious fight with an earnest fighter. Aichi attempts to refuse his PSYQualia, but Kai gives him the okay to do so as he doesn't want Aichi to hold back anything. At what seemed to be the final turn, Kai comes to accept that he lose to Aichi, but begins to hear the voices of his units and realizes that he was never battling alone and that his units and his friends have always been there with him through it all. At that moment, he pulled a heal trigger, giving him a chance to turn the battle around. Aichi notices that Kai's demenor has changed and asks if he has unlocked PSYQualia to which Kai only continued the battle, riding his newest ace unit: Transcendence Dragon, Dragonic Nouvelle Vague and proceeds to use it to defeat Aichi. Despite drawing a Heal Trigger himself, Vague's ability nullifies all of the opponent's Triggers, leading Aichi to accumulate six damage and lose. Kai and Aichi thank each other for having a great battle with Kai commenting that he doesn't need PSYQualia to have a great time playing Vanguard and that thanks to him he can be happy.
A few months later, Aichi and his class graduates from middle school and learns that he will be going to Miyaji Academy instead of Hitsune High like he and Miwa are. When asked why, Aichi replies that he is done running from his past, something that strikes a cord with Kai. Shin then announces the Card Shop Tournament and everyone begins having a good time. Kai then offers to battle Aichi, commenting on what he said earlier about not running away. After Aichi beats him, Kai notices that he is crying and asks why to which Aichi replies that he is happy seeing Kai happy.
Part 2 - High School Arc (Battle for Earth)
Before high school started for Aichi, he was part of the Asia's Vanguard Fighters Circut Championship matches. Kai watched as Aichi rose to the top and became the champion. During the award ceremonies, while everyone else was gushing over ULTRARARE, Kai pointed out that Suiko was the one who told Ren about PSYQualia. He would later hang out at Card Capital with Aichi and his friends.
It wasn't until the PSYQualia Zombie incident that he would get involved. Kamui along with Morikawa and his friends were infected with PSYQualia and intended to spread it through Card Capital. Kai and Miwa arrived on the scene to find that this was happening. Misaki informed them of the situation and that if they lost to any of them they would become a PSYQualia Zombie as well. Kai remained undetered and challenged Kamui to a fight to save him from the infection to which he laughed with glee. Despite Kamui's relentless attacks, Kai turns the tables with his new ace, Dragonic Overlord the Great, telling Kamui that someone who is satisfied with a power he was given will never overcome someone like him to continues to strive forward on his own merits. After winning, he claims that Kamui owes him and that he is cashing in on his debt by having him fight and revert Morikawa and his friends back to normal.
Soon after, Ren, Tetsu, and Asaka arrive at Card Capital to explain the situation at Fukuhara's school and the mysterious PSYQualia zombies running amok (little do they know no longer is an issue due to Ibuki 'Deleting' Sukio and undoing her spell). To be on the safe side, Tetsu forces Kai to accept that both he and Ren will be staying at his place while Asaka stays as Misaki's place. Kai gets flustered by this, but relents. He goes grocery shopping with Miwa to stock up on supplies but Miwa ditches him in fear of being a pack mule for his store bought goodies. Kai calls Tetsu to lend him a hand when he gets a call from Miwa to meet an old friend at Card Capital. Kai reunites with Ibuki for the first time in ages, but the friendly atmosphere turns sour when Tetsu reveals that he fought Ibuki with a weird clan and lost interest in Vanguard. Ibuki explains that his goal is to wipe out all Vanguard fighters and eventually Vanguard itself. Kai stands up to Ibuki and battles him, but gets defeated and supposedly 'Deleted' when Kai after the fight tells Ibuki that it was a great match before passing out. Ibuki leaves in a rage, planning his next steps to rid the world of Vanguard.
Despite being 'Deleted,' Kai continues to try and reconnect with Ibuki to which Miwa helps him and they arrive at the Tatsunagi Manor where Aichi and Ibuki have their fated showdown. Just as Ibuki reveals to Aichi that none of his broken bonds were ever fixed, Kai and Miwa tell him that in spite of recent events that they are still friends. Ibuki eventually lose the fight and rekindles their friendships, but is interupted by the Destiny Conductor, Takuto Tatsunagi, under the will the planet Brandt, and desires to fight Aichi in order to conquer Cray and the Earth. Kai offers to fight him in place of Aichi, but Ren is quick to point out that he can't fight with his link to his units severed as it is. However, everyone else steps up to fight him, but Aichi decides to battle him for the fate of the worlds. He stand in awe of the battle, commenting on how Brandt's power reverses the effect of Triggers and yet Aichi still persists with his battle. Aichi eventually wins and saves everyone in existence, even helping Brandt become part of the world. Later on, Kai goes to Card Capital and comments on how thanks to Aichi, everyone is free to play Vangaurd.
Part 3 - High School Arc (The Vanguard Koshien)
Sometime after the final battle between Brandt and Aichi, life resumes as normal for Kai with the exception of him being unable to rekindle his passion with Vanguard. With the Koshien just around the bend, Morikawa believes that with Kai's help, they could win so Kai promised that if he ever beat him once, he would join the club. It was at this time Kai continued to suffer the effects of being Deleted and Morikawa managed to pull off a surprising victory against him, shocking everyone around him.
One day, Kenji Mitsusada would approach him as he lays on a bench he frequents. Kenji invites Kai to join in him training at Voyage to which he refuses until he admits the reason is because he is lost and cannot find the shop. While walking, they run into Nagisa along with Tsuneto, Carl, and Kei. Kenji admits he got lost and they direct him to Voyage, forcing Kai to go along. Once there, he witnesses Kyou and Rekka battling with Kyou having fought ten times and not winning a single fight. He is a bit shocked to see him, knowing that he was one of Ibuki's victims. As he fights, Tetsu explains that despite being 'Deleted,' he has continued to play Vanguard and has determined that there is something amiss with his play. He goes on to say that if he can figure out what it is that's missing, that he, Kai, and everyone else who were 'Deleted' have a chance to recover. It is then that he meets with another Kagero player, Mamoru Anjou. He expresses his desire to fight him, knowing that he's been under the weather lately, but says that meeting him there today, along with bringing a certain card with him was some kind of fate and shows him a form that he has never seen of Dragonic Overlord: Dragonic Overlord The End.
Kai and Mamoru proceed to fight, with Mamoru claiming victory after victory. Despite Kai's funk, Mamoru continues to believe that he will master The End and wants to witness it for himself. During their fight, Kai reminises as to why he likes to use Overlord, seeing that he wanted to burn away those who would spur him simply because of what his parents did and he liked its re-stand ability, seeing as Overlord telling him that no matter what happens, he needs to stand back up and never back down. At the climatic moment of the match, Kai finally figures out what was missing from his Vanguard which was the belief in the words he used to get strong: Imagine yourself being strong! With this confidence restored, he proceeds to Ride Dragonic Overlord The End and use it's re-stand ability to gain four Criticals and defeats Mamoru. Tetsu comments that he got his rhythm back, but he states that it was only one match and that it would take more than that to get him back to normal. He does feel that he took the first steps to do so though. He proceeds to return The End to Mamoru, but he tells him to keep it as he felt the card was calling out to him and that he would like to face Kai at full strength during the Vanguard Koshien. He contempates this as he returns to Card Capital where he meets with Morikawa and asks that he fight him to regain his power once again. They proceed to battle with Kamui praying for Morikawa.
Eventually the Hitsune Vanguard Club participated preliminary tournament to determine who would be participating in the actual Vanguard Koshien tournament. Kai seemingly got his flow back and managed a win that allowed his school to be part of the tournament. Later that night, he sat in his room, looking at Dragonic Overlord The End, contemplating tomorrow's fights.
The next day, during the opening ceremonies, Morikawa would give the Fair Play speech and instead said that he was the leader of his school and that he would defeat anyone anywhere at any time but then said that it was Kai who said those words once he felt all eyes glaring at him. Once his name dropped, people started talking about him and he remained silent but annoyed. Days go by and the semi-finals are underway, but Kai, unable to sleep due to Miwa's snoring, goes off to a nearby park to work on his deck, losing track of the time. Miwa and Ibuki find him and they all reminise about their childhoods together before showing up nearly late for Miwa's match against Misaki. He loses, thus beginning the anchor match between him and Aichi. Aichi plays well until Kai plays Dragonic Overlord The End and decimates his forces until Aichi draws two Heal Triggers back to back to save himself. Aichi manages to outplay Kai, causing him to feel solace despite his oncoming defeat until Morikawa tells Kai that he can't quit until the end for the sake of the team. Kai manages to pull one Heal Trigger, but fails to pull another, ending the match with Aichi's victory and Miyaji Academy moving onto the finals. Kai thanks Aichi for a well played and serious fight.
He watches the last round of the tournament with the rest of his friends as Mamoru and his team arrive to watch as well. Mamoru tells Kai that he wished he could fight him in the final to which Kai replies that they can fight any time. Kai and the other spectators witness Miyaji lose the first two matches and Fukuhara's Asaka lose to Misaki, leading the next match to be a decisive one: Aichi VS Ren. Miwa asks who he thinks could win; he answers that he doesn't know. He watches as Aichi overcomes Ren's skills and brings the score to two to two with Ibuki and Naoki's match to decide the champion. During the match, he was shocked that one of ULTRARARE's idols basically cheered on Naoki. It was thanks to her pep talk that allowed Naoki to regain himself and defeat Ibuki, winning the Championship for Miyaji Academy. He then is surprised when Kourin Tatsunagi challenges Aichi to a match and is surprised and thrilled to be watching it. Afterwards, he relaxes at an afterparty for the Championship with Aichi approaching him and congratulating him on regaining his former self. Kai then states that it is because he fought a serious fight with him.
Kai has no presense in the first couple of episodes of this series. It is eventually discovered during an adventure involving a distorted Ren that he had never met Kai, raising a few questions as to why that is. Eventually it is revealed that the main reason for the distortion of the timeline was due to Shuka taking Blaster Blade away from Kai before he had a chance to give it to Aichi.
In order to restore the true history, Ibuki, Suiko, Emi, and Shuka seek out Kai. He's found to be living with his parents and is the complete opposite of how he is in the original timeline. Ibuki challenges Kai to a game of Vanguard to see how different he is from his original self, finding out that he never switched from Royal Paladin to Kagero. During the battle, Kai had a sense that something was wrong. Miwa, who tagged along with Ibuki and his friends, had reminded him of the card that really inspired him to play, Blaster Blade. Hearing this, Shuka gives Kai Blaster Blade in the hopes that he could somehow fix the timeline by giving it to Aichi. Miwa however, had other plans, dubbing himself as Pink Typhoon of the SK4, he told Ibuki and the others that he was ordered by Aichi to bring Kai to him, possibly to prevent them from returning the timeline to normal. In his attempt to capture Kai, Kai is seemingly perishes in an explosion, later revealed to be transported directly to where Takuto Tatsunagi was. Here he is told about the true history that should have come to place but had been distorted resulting in his current happier life.
Eventually Kai would join up with Emi's group helping them defeat the attacking SK4 by riding Blaster Blade through the magical girls' power. These battles would accumulate as he was later joined by Ren as Blaster Dark and face off against Aichi directly. In the final battle he along with Ren lent their power to an Ibuki who had ridden Majesty Lord Blaster, defeating the twisted version of Aichi. Following the battle, he would have a cardfight with Emi reminiscent of his first cardfight against Aichi in the true history. With the conclusion of the cardfight, Kai would be the one to return Blaster Blade to his younger self and in doing so restore history to its true form.
- As he lives alone, Kai learned to cook for himself. One of his best dishes, which Miwa is impressed by, is beef stroganoff.
- Since he goes to Hitsue High School, it is most likely that he lives in Hitsue town.
- Kai's English voice actor also voices Blaster Blade in the V Series anime.
- Kai's Seiyu, Takuya Satō, is notable for his portrayal in several other animes, a prominent one being JoJo's Bizarre Adventure Part 2 as Ceaser Zeppli.