|Gallery | Relationship | Quotes|
|Duel Monster statistics|
|Affiliation||Den Academy's Duel Club|
One day, Naoki noticed Yusaku asleep after class had already ended and introduced himself, noting that Yusaku has no friends. He was upset that Yusaku didn't remember him, as they had been classmates for over a month. Naoki tried to befriend Yusaku and showed off his new Duel Disk, only for Yusaku to criticize Naoki's lack of Dueling talent, but also pointed out that Naoki had good intentions. Naoki got upset at Yusaku's remarks and stormed off, telling him to Duel by himself. Later he went to watch Duels at Link VRAINS and was scared when The Knights of Hanoi attacked, and was surprised when "Playmaker" appeared.
Naoki asked what the Duel between Playmaker and The Knight of Hanoi was. A young man wearing an apron answered him that this was called an "Speed Duel". He was surprised that Playmaker used the Cyberse type and was happy when Playmaker attacked Hanoi's "Cracking Dragon" but became worried when the Dragon survived to the attack and Playmaker fell from his D-Board. After that Blue Angel saved Playmaker, Naoki cheered him to protect Link VRAINS. He worried when Playmaker is sucked into a tornado within the Data Storm and was relieved when Playmaker won the Duel. A few days later, in the classroom, he asked Yusaku if he had seen Playmaker in action before, Yusaku answered that he had not seen him. Naoki shouted at Yusaku if he considered himself a duelist. He told him that he checked Link VRAINS over to see if Playmaker was going to show up again on his electronic note pad and was horrified to see a Knight of Hanoi. He showed the knight to his classmates and was suprised when Yusaku disappeared.
|Main||Aoi Zaizen • Go Onizuka • Yusaku Fujiki|
|Den City||Aoi Zaizen's robot • Den City orphanage owner • Emma Bessho • Frog • Go Onizuka's manager • Hosoda • MC • Naoki Shima • Pigeon • Roboppy • Shoichi Kusanagi • Tanaka • Sato • Suzuki|
|SOL Technology||Akira Zaizen • Bishop • King • Knight • Pawn • Queen • Rook|
|The Knights of Hanoi||Dr. Kogami • Revolver • Specter|
|Other characters||Revolver's father • Shoichi's brother|