|“||Rip em' up! My avatar!||”|
—Phrase that became a habit, whenever he rides any unit as he prefers to
Naoki Ishida is a student at Miyaji Academy. Introduced as a bored youth who has no passion for anything, he follows Aichi Sendou to Card Capital after school one day where he learns of Cardfight!! Vanguard. While there, he has his first match with a new Narukami Trial Deck provided to him by the Shop Manager where he begins to understand how Aichi can be so different than what he was at school. After losing, Ishida purchases the Deck and runs off, wondering more and more about the game and Aichi. Naoki actually knew Aichi in elementary school before he transferred to another school, but never paid attention to him.
In episode 107, Naoki fought against Shingo Komoi, trying to "teach him a lesson" but was overwhelmed by Shingo's skill and lost. Proceedingly in defeat, he pleaded to Shingo to show him how to be a better cardfighter, which also manifested a rivalry between the two.
When Miyaji Academy went against Hitsue High, Naoki was selected to fight against Toshiki Kai. In the fight, Naoki was quite a match for Kai putting Kai at 5 damage by Break Riding Eradicator, Gauntlet Buster Dragon. The next turn, Kai had Break Ridden as well to Eradicator, Dragonic Descendant. With this, he obliterated through Naoki's defense and won the fight. Even though Naoki lost, Kai commemorated his skill and effort and agreed to fight with Naoki another time.
To find out who will be the co-captain of The Cardfight Club, each candidate wishing to be co-captain was put into a fight against another candidate. In this case, Naoki and Kourin were put up against each other. Naoki almost beat Kourin but did not manage to, and lost to her. Naoki was so upset that he had repeated "pathetic" to himself thinking that he wasn't worthy enough. Even though Kourin and Misaki were supposed to fight to find out which one of them will be the co-captain, both as well as Shingo agreed that Naoki truly wished to be the co-captain more than any of them and decided for him to be the co-captain of The Cardfight Club.
During their trip to Fukuhara High, Naoki faces off against Suiko Tatsunagi, unintentionally insulting her when he commented on her school uniform. He ends up losing after leaving himself wide open from using Armor Break Dragon's Limit Break. In their rematch, he plays a bit more carefully, not using Armor Break Dragon's Limit Break at first because it may get nullified like last time, but after getting backed into a corner, he pushes onward and gains a victory.
After their team gets knocked out of the High School circuit, he still hangs out at Card Capital to hone his skills. After school one day, he finds the secretary of the Student Council walking into a strange room and follows her. Afterwards, he ends up getting Reversed and challenges Aichi to a Cardfight which he loses, reverting him back to normal.
Later after Takuto Tatsunagi's message, Naoki begins to remember the circumstances of which he became reversed saying that the Student Council Secretary Maki Nagashiro was the one who Reversed Naoki and before they could get a chance to unReverse the others, everyone retreated. Upon arriving at Card Capital, Leon Soryu arrives to challenge Aichi only to be disappointed with his waivering thoughts. Naoki, seeing this as an opportnunity to get stronger and help Aichi, chases after Leon with Shingo chasing after him. He challenges Leon, but unfortunately cannot get a win off of him. Leon, in turn, decides to go challenge Kai and Takuto on his own, though he tells him to look after Aichi for him. After leaving, Naoki and Shingo decide to train each other and retool their Decks.
With the both of them psyched up more than ever, they decide to storm Miyaji Academy on their own and defeats almost every Reversed Cardfighter there but loses track of Shingo. Upon finding the Student Council President and Vice-President, he soon finds Shingo who became Reversed by Maki. When all hope seems lost while fighting Shingo, he is called to by the real Shingo reminding him of the Deck they made together to help Aichi defeat the Reverse, defeating Shingo and restoring him to normal with his new ace card, Eradicator, Tempest Bolt Dragon. He then recalled the location where he fought Maki and along with the President and Vice-President, found Maki and challenged her. Even when she talked about his loner nature and how Link Joker accepted it, Naoki stood strong, and through his passion, he was able to defeat Maki and finally liberate Miyaji Academy from Link Joker.
Naoki is first introduced when he sees Kai entering the physics room. He then encounters Kai again curious about Kai, having forgotten Aichi too. Kai then challenges Naoki to a cardfight when he notices Naoki is getting a reaction when he saw the deck. When Kai rides Blaster Blade he sheds tears remembering Aichi and vows to find him. He then claims he doesn't feel like cardfighting anymore and watches Kai and Misaki's cardfight.
After Misaki and Kai's fight Naoki has a dream about not being able to reach Aichi he later awakes in the Cardfight Club room. Naoki has an outburst of fustration that startles Shingo who just arrived at the Room Naoki asked Shingo why he was there and Shingo said he often comes here as it helps him relax. Naoki asked Shingo if he remembered the Club and Aichi but Shingo didn't.
During thier conversation they hear a voice and a man enters the room he claiming to know were Aichi is and tells Naoki that unless he defeats him he won't find Aichi. Naoki was overpowered by Mores's Megacolony deck and was rendered unable to stand his entire field and was almost defeated by Machining Spark Hercules Limit Break but he managed to survive wth 2 Superior Intercepts and the cards in his hand, He hears Kai's voice telling him to seek his Mate and move foward. Naoki draws then rides his new Vanguard Brawler, Skybeat Dragon and uses its Legion ability to call Brawler Skyhowl Dragon and defeats Mores who then retreats.
In episode 175, Kai appears with him and Miwa confronting Ren about Aichi. Later, Naoki went with the entire group to find the Quatre Knight's hideout, but it disappeared after Kai lost to Kourin. When the group went to Leon's home for training to beat the Quatre Knights, Naoki lost to Leon several times. After insisting to fight Leon again, Leon agreed if Naoki could reach a nearby island. Naoki tried for hours to get there using brute force and failed even with Kamui's help. He eventually succeeded another way and built a new deck, but lost to Leon again.
At some point, Naoki followed Raul Cera to the Quatre Knight's new hideout and brought the entire group there. Once inside, they were confronted by Raul Cera and Naoki volunteered to fight him as Naoki believed he was the weakest of the group. Cera allowed Naoki to win so that one of the seals on Aichi, and thus Link Joker, would be broken. After Kamui, Misaki, and Miwa had all lost their memories of Aichi, Naoki and Kai eventually made there way to the place where Aichi was being kept just as the last of his seals were broken. After Aichi lost to Kai, Noaki was one of the first to receive the now split seed of the void.
Naoki went to Misaki's Graduation Ceremony along with Aichi and Shingo. Then, as they were going to Card Capital they passed by a commercial shoot starring Team Ultra Rare and waved to Kourin. Naoki participated in the Card Capital Shop Tournament in the series finale.
G Season 2
Naoki appeared as a chaser during the Dragon Empire Quest, where he lost to Chrono.
In episode 9, Naoki and Shingo wanted to participate in the Zoo Quest, but were unable to due to them not having a third member. Luckily, Luna was nearby trying to enter by herself, so they recruited her. In the first round, Naoki savagely defeated the Megacolony fighters guarding the ingredients and fought with Chrono over them at one point. In the end, their team's dish was so bad that it caused Shingo to be poisoned after one bite so they lost the G Quest. Before Tokoha's fight with Christopher Lo, Naoki revealed to Team TRY3 that Cray was a real place and said he was rooting for Tokoha.
In the manga, he is known to be more reserved and students seem to avoid him. When he saw Aichi again, he was amazed at how much he had changed from the time he was in the academy to right now. Seeing how Cardfight!! Vanguard changed him, Naoki decided to try the game himself. At first, it was hard for him to grasp the concept, but he later on caught on and developed his own style.
In Volume 6, it was mentioned that he has an older brother who is currently in college. His brother is described as a "perfect college student" and is known to pressure Naoki into doing good in his studies. It also appears that he is not happy about Naoki taking an interest in Cardfighting as it was disrupting Naoki's studies.
- The well-known phrase that Naoki says in japanese is "ブチかませ" (Buchikamase), where the "buchi" is written as katakana. Due to that, the phrase can be translated differently.
- Naoki was the first character to Break Ride, although it was completely accidental.
- He's also the first one to Crossbreak Ride even though he was reversed at the time he did it.