After the intense quarterfinals, the U-17 World Cup competition has been whittled down to four formidable teams. Standing between Team Japan's quest for international glory is the nine-time tournament champion, Germany, and their star-studded team, pro player Jurgen Borisovich Volk at its helm. With both the momentum and the crowd's favor on the side of their opponents, Japan faces an uphill battle. Determined to avenge an earlier loss, Japan sends seven of their best—including team captain Houou Byoudouin—to challenge the German national team. But trying to reach the finals for the first time in Japan's tennis history may cause even these fearless players to crumble under mounting waves of pressure as they venture into uncharted territories.

Action Duels, which allow duelists to soar and swing alongside their Duel Monsters, are taking the world by storm. Due to an evolutionary breakthrough, the Solid Vision system is now able to provide Duel Monsters with mass. Yuuya Sakaki is Yuusho Sakaki's son, the latter being the founder of You Show Duel School in Miami City. Yuusho insists that duels are not a tool of war, but rather are to bring smiles to people and thus introduced the concept of Entertainment Dueling. However, at the height of his fame, Yuusho disappears and fails to attend his duel with Strong Ishijima, the Action Duel champion. Although scarred by this sudden leave, Yuuya vows to become an Entertainment Duelist like his father. Several years later, in the midst of a battle with Strong Ishijima, Yuuya's desperation to win brings forth a miracle. His pendant begins glowing, turning his cards into Pendulum Cards, which enables him to perform a Pendulum Summon—a summoning method unknown to the world and himself—gaining him fame overnight. As a result, Reiji Akaba, CEO of Leo Corporation and founder of the elite Leo Duel School, starts producing new Pendulum Cards to incorporate Pendulum Summoning into the system. Thus, the mysteries that surround Pendulum Summoning and Yuuya's father start to unravel, and Yuuya learns bit by bit what it takes to become an Entertainment Duelist.

The kingdom of Kouka is blessed with a beautiful princess whose childlike innocence charms all who come across her. Named Yona, she has grown up sheltered in the royal palace, shielded from any danger that may befall her. However, all good things must come to an end. Yona's perfect world comes crashing down when a heinous act of treason threatens to erase all that she holds dear, including her birthright as the princess of Kouka. Left with no one to trust but her childhood friend and loyal bodyguard Son Hak, she is forced to flee the palace. Faced with the perils of surviving in the wild with a target on her back, Yona realizes that her kingdom is no longer the safe haven it once was. Free from the shackles of naivety, Yona vows to do everything in her power to become strong enough to crush her enemies. With Hak by her side, she must piece together the remains of an ancient legend that might be the key to reclaiming her kingdom from those who conspired to steal it from her.

Ichirou Satou is an ordinary high school student who pretended that he was a hero by the name of Maryuuin Kouga back in middle school, which led to others frequently bullying him. Now that he has left this embarrassing phase behind, he does his best to avoid standing out and live a peaceful life, although he feels the world has become quite dull. But when he makes his way back to school one night to grab a textbook he left in class, he runs into a strange girl wearing a costume. This girl, Ryouko Satou, happens to be his classmate and is affected by the exact same condition that he once had, holding on to a delusion that she is someone else and dressing up to reflect this. The very next day, Ichirou is asked by his teacher to become friends with Ryouko, to which he adamantly refuses, unwilling to be reminded of his own history. When he sees that she is being bullied just as he once was, however, the boy makes it his responsibility to take care of her and break her free from that which what once plagued him—the perfect job for Maryuuin Kouga.