Aichi's Cardfight Club is attracting attention all around the school as male classmates (who are mostly interested in being with Kourin) have him teach them the rules of Vanguard and again attempt to play against Kourin in order to be inducted to the club but to no avail. Additionally, the female students gossip about a rumor that claims Aichi only started the club to get close to Kourin, which makes Misaki worry. Aichi tries to ask Misaki to join the club, but she declines because of her job at Card Capital.
Kourin gets an unsettling feeling that there is someone watching her, with Naoki suspecting that it could be a stalker. Naoki eventually confronts the stalker who turns out to be a classmate, Shingo Komoi. Naoki threatens to beat him up, but Shingo suggests to settle things with a cardfight instead. Despite modifying his Narukami deck, Naoki's inexperience at Vanguard causes him to struggle against Shingo's Murakumo deck. After some taunting from Shingo, he reveals that the one who he has been watching is not Kourin, but it is actually Aichi, who he highly admires. Shingo defeats Naoki, who recommends for him to become a member of the Cardfight Club. Aichi and Kourin let Shingo join, thus bringing the total members to four. Unbeknownst to Aichi and his friends, another student observes them from afar and then walks away with the intention of reporting the Cardfight Club's disruptive behavior to the student council president...