A youngster with a big mouth and the skill to back it up. He's very enthusiastic and energetic about Vanguard and doesn't care who his opponent is so long as they are not weak in his eyes. He hates being looked down upon because of his size and age. He also has a crush on Aichi's little sister, Emi, and constantly vies for her attention, even going as far as to refer to Aichi as his older brother.
Kamui is almost always accompanied by his two friends Reiji Uno and Eiji Saga. Their usual routine is that after one of Kamui's boasts or while cheering for him, Reiji would make a comment, and Eiji would abbreviate what Reiji just said and add "-ssu!" ("yo!" in the dub) at the end.
Kamui is the second person to defeat Aichi in a game of Vanguard. Kamui has commented that he likes to take the second turn at the beginning of a game as doing so gives him the first chance to attack.
Kamui has used a Nova Grappler deck since the beginning of the Cardfight!! Vanguard series all the way to the current Vanguard G; he has changed his deck compositions many times in order to become stronger, but he has never changed his clan (this was revealed in the events of Link Joker to be because of a promise he made to Daimonji Gouki when younger).
His strategy when fighting is to push through with brute force, supported by Nova Grappler`s signature ability of standing rear-guards to enable further attacks. Kamui has also his own sense of justice and can hold a grudge and distrust against people who used Vanguard for evil means such as Kouji Ibuki.
Kamui has demonstrated the ability to break the 4th wall, able to literally tear apart Chrono's recounting of Nagisa's story as if it were tangible and made of paper. He is currently the only character shown to be capable of doing so.
An ambitious cardfighter who regularly takes on opponents several years his senior. Kamui has an intense crush on Aichi's sister Emi, and most of his actions in the series revolve around impressing her.
Years ago he was bullied for being short, but Daimonji Gouki eventually helped pull him out of his depression. As time went on, Kamui learned from Gouki that strength was more than a physical concept. He soon became a regular of their shop and discovered his clan, the Nova Grapplers and to this day stuck by his clan. However, he wanted to truly test his skills against his shop so he decided to enter the VF Circuit on a different team; this decision later landed him with Card Capitol`s Team Quadrifoglio, along with Misaki, Kai and Aichi.
Inside Team Q4, Kamui competes with Kai for the top spot as the best raw fighter, but where Kai is cold and emotionally distant, Kamui is ruled by passion and impulsive outbursts.
He shown to be battling against Izaki when Aichi went to Card Capital to buy a booster pack. He won the match and with his two friends, Eiji Saga and Reiji Uno, started to boast about how he was the strongest player there, which didn't really win any support from the other players, just annoyance. When Aichi asked if he could fight him, Kamui outright said no as Aichi looks like a beginner and he does not want to tarnish his record by fighting a newcomer. In the end, Morikawa ended up fighting and losing to him. Then Emi showed up from the doorway and Kamui got the "love at first sight" sign. He tried to impress her, but she instead moved to where Aichi was and started to drag him home. When he and his two friends saw this, they thought that Aichi and Emi were boyfriend and girlfriend.
The next day, Kamui came back to the shop to battle Aichi. Along the way he taught Aichi some pointers to help with his skills in Cardfight while hoping that Emi would leave Aichi for him instead. Although Aichi was winning, Kamui won in the end. Aichi was confused at what Kamui wanted when Emi came to the shop. He and his two friends were annoyed at Aichi when Misaki said out loud that she couldn't really figure which is the older one here. They were confused until Misaki told them that Aichi and Emi were brother and sister. Then Kamui started to call Aichi his "older brother" in hopes that he can win approval from Aichi so that he wins Emi's heart.
Kamui now goes to Aichi's old school Hitsue Middle School and was the fifth member of the High School's cardfight club during the intermural cardfights as the club itself only has 4 members. During the intermural fight, he faced off against Misaki's new Genesis deck but was unable to finish her off, even with his new Break Ride.
Later, when he heard news of Nagisa attending the open house for Miyaji Middle School (where Emi and Mai now attend), he rushes over only to see the school being taken over by a reversed Gouki. After saving Gouki, he is confronted by a Reversed Nagisa, though the appearance of Ninja Master Neo allowed him to pursue Rekka, who had just taken Emi and Mai with her. He manages to reach Rekka and defeat her and release the girls. Joined by Gouki and Nagisa, the group defeats the other Reversed fighters only for Kamui to run away in embarrassment after Emi thanked him, only to run into one more Reverse fighter, Kourin. Though he fought well, he was caught off guard by Kourin's Quintet Wall and lost just as Aichi had gotten back to Miyaji High School and became Reversed.
Days later, he confronts Aichi's group in order to challenge Aichi to a Cardfight. He is reminded of their past and how, at the beginning, Aichi couldn't even stand up to Kamui and now Aichi is miles ahead of him. But through their Cardfight, Aichi states that it's their bonds that make them stronger and that the brave Kamui who takes all challengers head on, will always inspire the hesitant Aichi. And with that, along with Aichi's new Crossbreak Ride, he defeats Kamui and releases Kamui from the Reverse.
Kamui, who has lost his memory regarding anything related to Aichi, is revealed after an intra-shop tournament that he feels like something's missing; he then decides he needs a challenging fight after cardfighting many "weak players" after following advice from Gouki. Gouki then tells him of a really strong cardfighter, Kai Toshiki, stating that he has never won against him before. Kamui then heads to Hitsue High to fight Kai, only for Naoki to fight him instead after Kamui bad-mouths Aichi, whom he has no memory of. During the cardfight Kamui began to have fuzzy images of Aichi after Naoki tried to call out to him several times. Still, it was only until Naoki activates his Legion and defeats Kamui does he remember who Aichi is.
After Kai and the others face off against the Quatre Knights and Kai decides to leave them to fight against them alone, Kamui challenges him to keep him from running away from the group. In their fight, he reveals that he is happy that Kai is going out of his way for his friends as opposed to his loner attitude in earlier seasons saying that he now trusts his mates and is mad that Kai is pushing everyone away again. With his Legion, Kamui defeats Kai showing him that like the Vanguards, he relies on his mates and rear guards to help them out knowing the danger, just like their situation right now as Kai accepts Kamui and the others as partners in their search for Aichi.
After the fight, he and Misaki are seen at the airport, looking for Mitsusada Kenji (aka Koutei) to ask him, who has been attending tournaments worldwide, about world-famous fighters, in particular Gaillard and Neve who have been identified as the former and current Vanguard European Circuit champions as well as members of the Quatre Knights. There, they are met with Koutei, together with two other world-famous fighters, Ratie Curti and Raul Serra.
G Season 1
Kamui becomes a student at Hitsue High School and works part-time in Card Capital 2, though he often leaves his post for various reasons, leaving Shin pretty frustrated sometimes. He helps to introduce Chrono Shindo to Vanguard. He takes a very special interest in Chrono not just because of his mysterious Gear Chronicle deck but wants to help him grow as a cardfighter. In G, his popularity seems to have grown a lot compared to the earlier seasons; his recognizability is about the same as Anjou, who is the Kagerō clan leader.
When Chrono was looking for teammates to compete with him at nationals (and failing due to his poor social skills), Kamui chimed in and assembled Team TRY3. Kamui attempted to gauge their ability to work together only to find that they despised each other. Kamui ranted that they could never win at nationals because they can't work together well, so Chrono, Shion, and Tokoha agreed to put aside their differences and work together just to spite Kamui.
G Season 2
Kamui reappears in Cardfight!! Vanguard G: GIRS Crisis. He seems to know about the new G Quest for he informed Chrono that he could become the First Generation Clan Leader for Gear Chronicle. Later, he is seen in a train sleeping until awakened by Ibuki's message.
He makes an appearance in episode 5 with Kai, Miwa, Naoki and Shingo and told TRY3 that they will be participating in the Dragon Empire Quest. In episode 8, it was mentioned by Misaki that he was taking extra classes due to failing grades, but at the end of the episode it was implied that he had been searching for Ryuzu Myoujin, saying that he and his friends had to put their faith in TRY3 for the upcoming battle.
Kamui was mentioned again in episode 9 by Naoki when he told TRY3 about Planet Cray being real and that they should talk to Kamui about it.
G Season 4
Ever since Chrono took over his job at Card Capital 2, Kamui has since taken a part time job at the original Card Capital. He is now in his third year of high school.
Quite boastful about his skills in Cardfighting, he openly shouted out loud in Card Capital that he would fight against the strongest Cardfighter in this shop. Misaki told Kamui to be quieter or she would ban him, prompting him to apologize. Misaki pointed to Miwa, Aichi, and Kai as the strongest fighter. Miwa said that he was the strongest, but Kai said that he never won against him then Miwa said that he lost to Aichi then Aichi said he lost to Miwa. Kamui was confused and decided that they were the strongest group so he will fight them all.
Miwa then proceeded to fight against Kamui, but lost. Miwa didn't understand why he lost. Kai explained that Kamui was strong so he told Kamui to fight against Aichi. Aichi, at first, he wasn't really confident on the match though Kai said that Aichi was good enough to advance to the next step. Kamui couldn't protect himself so he lost with Aichi winning. He announced that he wanted to be more like Aichi, but Miwa said that he should be more like him. The circle mess once again caused Kamui to freak out about what he should aim to be.
Kamui plays Nova Grappler decks in all of his appearances, his strategies are usually just plain brute force while being supported with various card skills or standing his units. Kamui himself stated that Nova Grappler is his ideal clan and will never switch it.
Throughout both Vanguard and Vanguard G series, Kamui has been seen using a wide variety of different Nova Grappler archetypes. While he usually keeps one deck as his main, it is shown that he keeps his previous decks and ocassionally uses them.
During the begining of the series, his starter vanguard is Battleraizer and his ace is Asura Kaiser. During the first shop tournament, his deck focus switches to Mr. Invincible and he adds Rock the Wall to his deck to aid his soulcharge. During the second regionals, his deck changes its focus to the Blau ride chain. He also focuses more on standing his units.
In season 2, his deck receives additional cards from the Breaker of Limits booster pack and his starter vanguard is changed to Beast Deity, White Tiger. Before the Singapore stage, he edits his deck and focuses on Beast Deity, Azure Dragon and using its Persona Blast. With this deck, he wins in all his matches in the Singapore stage. His winning streak with this deck is stopped by Tetsu during episode 78.
After his visit to the vacation island, he rebuilds the deck with a Raizer build, featuring Perfect Raizer as his main Vanguard. As Perfect Raizer removes his own Rear Guards to power up, Kamui makes up for his losses by using cards with skills that allow him to draw, such as Street Bouncer and Magician Girl, Kirara, or by Soulcharging Raizers from the Deck by reintroducing Mr. Invincible.
Kamui then reverts back to his previous Beast Deity tactics for the last leg of the Circuit. However, this deck has a more balanced strategy between offence and defence, with Kamui still using draw skills and Draw Triggers from his Raizer deck. His ace card is the crossride Ultra Beast Deity, Illuminal Dragon, which he combines with various stand strategies such as resting his new Beast Deities, then standing them, giving them extra power.
Reversed Kamui changed his Beast Deities deck to a Яeverse Beast Deities Deck with a focus on the another Crossbreak Ride; Deadliest Beast Deity, Ethics Buster "Яeverse". During the Break Ride turn, along with the Limit Break which stands Ethics Buster "Яeverse" again, he can go to up to eight attacks in one turn which exhausts a player's hand if they want to guard that many attacks.
Kamui goes back to using the Raizer series but with the introduction of some new cards. After remembering Aichi, he rebuilt his deck to use Ultimate Raizer Mega-flare and Ultimate Raizer Dual-flare legion to not only get an extra critical but using his rear-guards skill like Ultimate Raizer Dual Flare to stand up after they attack as well as having Carvingraizer to give a boost to his Legion vanguards.
The great Kamui rides... the impervious hero exploding onto the scene! Mr. Invincible!
Soar into battle the king of keeping it real! Mr. invincible!
I released that raging, evil soul! I ride Brutal Jack!
3 times the dragon means the 3 times the force! Get ready for this ride it's Brutal Jack!
With the mane of courage and the roar of justice! I ride the king of all cats, Lion Heat!
The Great Kamui does an awesome ride! The absolutely invincible, armored... ...Stern Blaukluger!
The great Kamui does his ultimate ride! It's my pleasure to introduce you to unstoppable force of Stern Blaukluger!
The great Kamui brings out the big,bad Robot! I ride, Asura Kaiser!
Sleeping blue dragon in the blue star... My voice is heaven's decree! Awaken and descend to Earth! I ride... Beast Deity, Azure Dragon!
Sleeping dragon protecter of the Planet Cray! Heed your masters call! Show them how Nova Grapplers roll! The great Kamui rides Beast Deity, Azure Dragon!
Raizer series... the great me rides the ultimate machine! Answer your master, Raizers! Gather together here and form Perfect Raizer!
Raizer series! Answer your master and form into the ultimate perfect raizer among the raizers! Ride, Perfect Raizer!
It's the pinnicle of the Raizer Series, comin' out for a power ride! Combining the strengths of all my Raizer units to create the ultimate Raizer, Perfect Raizer!
The sacred glow that is proof of hope... Envelop the world with your light! I crossride Ultra Beast Deity, Illuminal Dragon!
A humble call from the bachelor king to the ultimate battleroid unit! I ride into victory with Ultra Beast Deity, Illuminal Dragon!
The Guardian of Cray his ultimate form light up these Dork Irregulars! Ultra Beast Deity, Illuminal Dragon! The Great Kamui Crossrides!
Your holy light is the proof of hope! Envelop the world with your light! Ultra Beast Deity, Illuminal Dragon! The great Kamui break rides ontop of Ethics Buster!
This is the rumored beast god! It fists are absolutely invincible! It crushed innumerable opponents! The newest! The greatest! The zenith! The great Kamui rides Strongest Beast Deity, Ethics Buster Extreme!
Go! Burning Fire! Roaring Thunder! The great Kamui break rides the furious strongest Beast Deity, Ethics Buster Extreme!
The strongest on earth! Anxiety, evil, and anguish, grovel before Kamui the Great! Crossbreak ride! Deadliest Beast Deity, Ethics Buster "Яeverse"!
A flash of light that pierces the darkness of space! The great Kamui rides Ultimate Raizer Mega-flare!
Seek mate! Dark crimson magma lying deep underground and blue sky surrounding this planet in the heavens! Now, awaken and line up to protect the home planet! The great Kamui's Legion!
The great Kamui's seek mate! Blue light of a star born in the darkness of space! Magma breathed in and out by a pulsating scarlet star! Explosive descent! Mega-super-ultra-special power! Ultimate Raizer Dual-flare! The great Kamui's Legion!