Introduced as someone who in the beginning was timid and shy. Aichi gradually gains the confidence in himself and his deck in order to fight against the best Vanguard Players and in turn meets new friends and allies along with new rivals. During the fateful encounter with Kai, who was still a friendly teenager, he gave him the card Blaster Blade, telling him to imagine himself big and strong, like the royal knight depicted on the card. Aichi couldn't picture himself any stronger at that moment, but the card gave him courage. He constructed a deck in the hopes of finding Kai and having a cardfight with him, but shortly after their encounter, Kai had apparently moved away. He eventually transferred to a different school after his mom got upset over the constant bullying. Aichi lives with his mother and little sister, Emi. It is shown that Aichi isn't interested in school that much and his sister always woke him up, though this behaviour disappears after he starts playing Cardfight!! Vanguard.
Aichi uses a Royal Paladin Deck. His strongest cards are Blaster Blade, Alfred "The King of Knights," Soul Saver Dragon, and Majesty Lord Blaster. In his final confrontation with Ren, Aichi adjusts his deck so that Blaster Dark is mixed in with his Royal Paladins so that he could use Majesty Lord Blaster's abilities to the fullest.
In season 2, Aichi's deck changes into Gold Paladin clan, with his Ace card being Incandescent Lion, Blond Ezel from Kourin. Aichi now puts in more effort to superior calling units from the deck, using the Blade Feather Valkyrie / Flash Edge Valkyrie combination, as well as Nimue and Viviane, and units that can activate their skills upon being called from the Deck.
In season 3, Aichi has decided to use the Gold Paladin as his main deck. His deck consists of the Liberators cards which were originally Royal Paladin units along with his ace being his reborn avatar- Blaster Blade Liberator, though later Aichi modifies his deck around his new Crossbreak Ride card Liberator of Bonds, Gancelot Zenith in order to creating colossal units once cross ridden, and units like Viviane and Escrad will help Aichi fill up his field, so he can preserve his hand.
