"Aichi Sendou" is the main protagonist of the Cardfight!! Vanguard (V Series Anime), and is the president and founder of the Miyaji Academy Cardfight Club. He has the mysterious power to hear the voices of cards. In the second arc of the V Series anime, he was considered to be the Vanguard of Earth during the fight for Planet Cray. During the events of Cardfight!! Vanguard Extra Story -IF-, the story follows a version of Aichi who did not receive Blaster Blade from Toshiki Kai, instead becoming the series' main antagonist.
According to Kerokero Ace September 2011, Aichi's surname is written with the kanji for vanguard (先導), the forward element in a military formation (and, of course, a reference to the title of the franchise). His forename primarily refers to the Aichi prefecture of Chubu, Japan. This follows a general trend in Vanguard of using historical names for characters. "Aichi" as a name originates from the third volume of the Man'yōshū, Japan's oldest collection of poetry, where it was referred to as Ayuchi, the Ayuchi-gata tidal flats.
He is weak, shy, and tends to be nervous, due to being bullied throughout most of his childhood. Despite that, he has a gentle heart and sees the good in others, even being friendly towards his (former) bullies. As the series continues Aichi gradually becomes more confident in himself, accumulating to his valued position as leader of the Miyaji Academy Cardfight Club.
When under the influence of the PsyQualia Zombie infection, Aichi is shown to have become ruthless and cruel during a cardfight. He is seen having an unsettling smile on his face and even teases his opponent during a fight about their trigger pulls. He keeps his politeness but it his tone of voice makes it sound sadistic.
As shown through the events of Cardfight!! Vanguard Extra Story -IF-, had Aichi never come into contact with Vanguard through Kai, he would have maintained his timid personality rather than gaining confidence in himself. As opposed to the former's kind outlook towards vanguard, this version of Aichi held a conflicted hatred towards the game.
Aichi is a boy with long blue hair with a right hair bang which is his signature style. He is first seen in his Hitsue Middle School uniform which is mostly all gray with white linings along with a red sweater under it. He is quite particularly short compared to other characters of the same grade. Upon enrolling in Miyaji Academy, his school uniform now consists of a black blazer and pants, a white button up shirt and a red tie.
His casual attire consists of a light blue sweater with black accents on the shoulders and wrists, a maroon turtleneck sweater underneath, faded blue jeans, and black boots.
When he was younger, Aichi Sendou was a very shy and lonely boy who was frequently bullied at school. A fateful encounter with Toshiki Kai, who was still a friendly teenager, resulted in him receiving the card Blaster Blade and becoming introduced to Cardfight!! Vanguard.
Initially, Aichi is shown to be student at Hitsue Middle School, having his Blaster Blade forcefully taken from by Katsumi Morikawa. Heading to Card Capital in order to reclaim the card. Here, he once again meets with Kai and after a cardfight between the two, the story unfolds as Aichi comes out of his shell and gains new friends. He becomes particularly goods friends with Kai, Misaki Tokura and Kamui Katsuragi, temporarily forming Team Q4 and facing off against Team NwO.
It was in his fight against Leon Soryu of Team NwO that his mysterious power first showed itself. Later on, after cardfights against Kyou Yahagi and Tetsu Shinjou of Foo Fighter Organization (V Series), a group of cardfighters who had been terrorising local cardshops, he learns the name of this power, PSYqualia. Both this power and his connection with Kai would eventually lead him to another with the same power, Ren Suzugamori the leader of Team Asteroid. Unlike Aichi, Ren had been corrupted by his power only freed from its influence after being defeated by Aichi.
Following his exploits at the Asia Circuit, Aichi progresses to high school, enrolling at Miyaji Academy. Here he decides to start up a Cardfight Club soon joined by Kourin Tatsunagi, Naoki Ishida, Shingo Komoi and Misaki. Along with friends new and old, Aichi faced the PSYqualia Zombies that were increasing spreading as well as the rogue Kouji Ibuki who has deleting the connection that players had with Vanguard. Aichi ultimately fell to the PSYqualia zombies becoming one himself after losing to an afflicted Naoki. As a PSYqualia zombie his personality took a cold shift losing out on his usual kinder self, even turning against his friends. Despite being in this state he defied the orders of his master, the Destiny Conductor, and started a fight with Ibuki after learning that the later had deleted Kai. The result of this cardfight allowed Aichi to break free from the influence of the Destiny Conductor, turning against him. Following the defeat of the Destiny Conductor, everyone who had become a PSYqualia zombie under his influence were returned to normal, however some of the events that had transpired would be rendered to have never happened, the most significant being Kourin's place in the Cardfight Club.
Even so, they would later reunite albeit temporarily, after the Cardfight Club manage to become the victors of the Vanguard Koshien.
The events of Cardfight!! Vanguard Extra Story -IF-, follow an Aichi whose life would have been exactly the same had it not been for a distortion created by the Card Fairy Shuka that resulted in a world line in which Kai and Aichi never met and as such, Blaster Blade never fell into his possession. Maintaining his timid and hurt personality through his life he would learn of the life he should have lived from Takuto and Kourin, who had travelled to this world in order to return the world to its true history. It was through this meeting that he learnt of Kai, a person he had never met yet the memories they should have had together haunted his dreams, in the distorted world Kai's family was in a much better position. Unable to withstand the flow images caused by his memories, the shackles on his imagination broke, his PSYqualia unearthed, growing rampant and twisted creating Sanctuary and knocking out Kourin. He would then form the organisation Jammer, reigning as the lord of the Sanctuary. Employing SK4, he sent out Jammer to eliminate Vanguard from the world causing even further distortions.
For much of the series, Aichi stays in the background within Sanctuary after an initial interaction with the Blaster Pair in which he sent them flying out of the castle. His first proper interaction occurs when Shuka tries to give Blaster Blade to him, but the sight of the card causes his imagination to break loose again and he captures Shuka, bringing her to Sanctuary. The other members of Shuka's group (Emi, Ibuki, Suiko, Ren and Rekka) are captured by the SK4 and brought to the castle. Though they break free and go on the attack, their trump card, Majesty Lord Blaster is ridden by Aichi. Though Emi and Shuka's group escape, Aichi maintains hold over the Majesty Lord Blaster card and encases it in crystal in the same room holding Takuto prisoner. Using the power of the card, he would then create a barrier that prevented others from interfering with the source of his distortion, Shuka taking Blaster Blade from Kai.
Though the magical girls use the power of Blaster Blade and Blaster Dark to destroy the barrier Aichi had set up, he appears in the form of Majesty Lord Blaster to reapply the barrier and stop his enemies in their tracks. Ultimately, Shuka deprives Aichi of the power of Majesty Lord Blaster by setting ablaze her binder, releasing the cards she had kept with her. This causes Vanguard to be erased from the world, however Aichi finds himself still conflicted with the choice to eliminate Vanguard. Having obtained the Akashi Book, Aichi now proceeds to bring about an end to both himself and the book by sinking both into the ground with Sanctuary. Once again he is confronted by Emi who allows Ren and Kai to ride Blaster Dark and Blaster Blade respectively, though they stand no chance against Aichi until Ibuki arrives. Holding the Majesty Lord Blaster which had left Aichi, Ibuki in turn rides the card taking both Ren and Kai's power, defeating Aichi. Following his defeat, history is restored to it true form.
Following on from the start point of the -IF- series in the now restored history, Aichi heads to a Vanguard event along with Emi, meeting with Ibuki along the way. Here he participates as part of the event along the true history's 'Jammer' and Shuka.
- The -IF- Aichi shares some similarities with his original series counterpart during the events of Cardfight!! Vanguard: Legion Mate