Aichi Sendou is the main protagonist of the Cardfight!! Vanguard anime, a character who transforms from a timid, bullied child into a confident and powerful cardfighter. As a young boy, he was frequently picked on and lacked self-confidence, but a fateful encounter with an older boy named Toshiki Kai changed his life. Kai gave him the rare card Blaster Blade and encouraged him to imagine himself as strong and courageous as the knight on the card. This act gave Aichi hope and purpose, leading him to build a deck in the hopes of one day meeting Kai again for a proper cardfight. He lives with his mother and younger sister, Emi. Aichi is gentle, kind, and empathetic, often seeing the good in others, though he remains shy and socially unsure in everyday situations. However, once he engages in a cardfight, he becomes intensely focused, perceptive, and determined, displaying a strategic mind and a strong desire to win. His motivations evolve from seeking Kai’s acknowledgment to protecting his friends, the game he loves, and eventually both Earth and the parallel planet Cray. His key relationships include Kai as his inspiration and rival, his teammates Misaki Tokura and Kamui Katsuragi, Kourin Tatsunagi as a close friend with romantic feelings for him, and Ren Suzugamori as a dark mirror. Aichi possesses a power known as PSYqualia, which allows him to hear the voices of his cards and glimpse the future during a fight, though it can be corrupting if not kept in check. Later, his abilities expand to include real-world powers such as teleportation and manipulating memories. As a fighter, he primarily uses the Royal Paladin clan with his avatar Blaster Blade, later transitioning to the Gold Paladin clan under certain circumstances. His journey sees him grow from a weak, crying child into a leader who founds a cardfight club, faces existential threats, and ultimately sacrifices himself to protect others before being saved by his friends.