Season 4

After dreaming about meeting Blaster Blade, Kai rushes off to cardfight with Aichi. However, he's in for a big surprise...

Even Misaki who has better memory retention lost the memory of Aichi. Kai and Misaki enter into a cardfight, and Misaki gets a glimpse of her first cardfight but her opponent is covered by a shadow. She is wondering why her usually vivid memory is so blurry.

At the secret moon base, the Quatre Knights send a butler called Morres Pennyworth to break Aichi's friends. Shingo lost his memory of Cardfight Club started by Aichi. In front of Naoki confronting Shingo about it, a mysterious butler who throws out a hint of Aichi's existence appears.

Kai continues to seek the existence of Aichi. To tell Kai the warning told by a mysterious butler, when Naoki and Misaki arrives at Hitsue high school, Kai is facing Miwa.

Kamui, who is on Team Handsome with Gouki spending his free time fighting. Although he has busy days, he has an empty feeling for some reason. Naoki fights Kamui to help him remember Aichi.

Toshiki Kai visits Card Shop PSY where Aichi has been before to find a clue about Aichi, where he encounters Olivier Gaillard the first Quatre Knight who challenges him to a fight!

When Naoki and Misaki are walking in the park, they meet a big man surrounded by many cats, and one of them is sub-manager. The man recognizes Naoki and Misaki, and then gives them his name - Philip Neve. And he cautions against them not to seek Sendou Aichi anymore.

Kai knew his mates also are in danger to seek Aichi. The next day, Kai said, "I’ll seek Aichi alone from now on." to Misaki, Kamui and others, then leaves. But Kamui stands up against Kai who tries to go alone.

Misaki and Kamui heard the leader of "Team Caesar", "Koutei". Kenji is coming back temporarily to Japan, so they go to the airport. Misaki and Kamui arrived at the airport and meet a young girl named Rati who is looking for Serra. In the process, Rati gets stuck in a trash can. Kamui and Misaki help her out, only to find that she is too interested in the doughnut store to pay any attention to them.

Having encountered the illusive Rati at the airport, Misaki challenges her to a Cardfight. However, Rati reveals the true power hiding behind her innocent smile with the Shadow Paladin clan...

Raul Serra has the ability as the South American Champion of Vanguard. Serra launches attacks to Kamui with a cold smile that makes him feel icy.

In order to find out more about Aichi, Kai visits Ren once again. Upon arrival, the two start a fight in order to understand each other's feelings.

Kai and the others arrive at the place indicated by Ren, see a strange-shaped megalithic site. When they step closer to it, the light floods in from the megalithic site, and Olivier Gaillard appears?!

The battle between Naoki and Gaillard has ended. Naoki, who lost, faced his judgment. Then, Kai challenges Gaillard but Kourin appears and challenges Kai to a cardfight.

Kai and the others visit Leon to undergo special training in order to strengthen themselves before they can face Quatre Knights again.

Kai and others visit Leon’s home “Island of Souryu”. While Naoki and Kamui are training hard with Leon, Kai and Misaki are still stuck in the shocks about Aichi and Kourin.

Naoki Ishida sees Morris Pennyworth, a butler of the Quatre Knights, who Naoki fought off before. Naoki spies on him and finds the door that leads to where the Quatre Knights and Aichi are. Upon arriving, he and the others encounter Raul Serra. Naoki challenges Serra and the fight begins.

The fight between Naoki Ishida and Raul Serra who is one of the Quatre Knights continues.

Neve of the Quatre Knights blocks the path. Miwa finds himself overwhelmed by Neve's power. But in Neve's hidden past lies...

Trying to avoid her previous loss, Misaki once again challenges Rati. However, in addition to winning, Misaki also aims to teach Rati the meaning of "friendship". Will Misaki's wish be granted?

Kamui challenges Gaillard, who is protecting Aichi's seal. Kamui, who turns his friendship with Aichi into his own power, launches a fierce assault on Gaillard, who finds himself fazed. The bonds between mates, or Gaillard's loyalty; who will win?

Gaillard, who had pledged his absolute loyalty to Aichi after saving many lives including Gaillard's friends, reveals the reason why he became one of Aichi's faithful Quatre Knights.

Based on their own beliefs, Kai, his friends and the Quatre Knights had been engaged in a fierce battle with each other. Only 2 of the seals are left, but out of nowhere Raul Serra returns to lift Aichi's seal.

Link Joker has control over Aichi. Serra's intentions are revealed and he manipulates his fellow Quatre Knight Neve to fight Aichi. To undo the spell on Aichi, a fierce fight between Neve and Aichi happened.

Raul Serra, who betrayed Aichi, approaches Rati Curti in order to break the final seal on Link Joker. In order to stop Raul Serra's ambition and protect both Aichi and the Planet Cray, she challenges him to a fight!!

Raul Serra is a man with a burning obsession to make himself the strongest he can be. And then, in order to make his ambition come true, Serra proceeds to challenge Aichi.

Raul Serra has obtained the overwhelming power of Link Joker, and it proved to be too tough for Olivier Gaillard. But, despite how desperate things are, a blue flame ignites inside Gaillard's heart and shines on the darkness of despair.

Kourin stands in the way of Kai and his mates on their way towards Aichi. Naoki, who sees this, asks Kai to let him fight her on behalf of the bonds they shared as club members.

Kai is trying to rescue Aichi, and Gaillard is trying to protect Aichi. While both of them have different beliefs, the two of them share a connected fate.

The decisive battle between Aichi and Kai has started. In the middle of the fierce fight, Aichi showed Kai his new completely changed Blaster Blade, as proof of the bonds they currently share.

Aichi's Blaster and Kai's Dragonic Overlord face off against each other in the Sanctuary. However, Kai finds himself forced into a corner by the overwhelming strength that Aichi possesses.

Time has passed since the battle on the Sanctuary and the graduation ceremony for Kai, Misaki and Miwa is fast approaching. Aichi finds himself working tirelessly to complete the farewell script for the ceremony, but Kai isn't ready to see him yet.

After the graduation ceremony is over, Aichi and his friends participate in a tournament held at Card Capital. There, Aichi found a lot of his friends and rivals have gathered.