Introduced as a bored youth who has no passion for anything, Naoki followed Aichi Sendou to Card Capital after school one day and learned of Cardfight!! Vanguard. While there, he has his first Vanguard match against Aichi with a Narukami trial deck provided to him by the shop manager; Naoki finally begins to understand how Aichi can be so different than how he was at school. After losing, he purchases the trial deck and runs off, becoming even more curious about the game and Aichi.