During summer break, Tetsuo asks Sakie to join him on patrol duty for the local summer festival, which both the demis and Himari and her friends go to. As each group decides to check out a nearby shrine, they get spooked by some strange occurrences, which turn out to be each other. As the next term begins, Tetsuo converses with an invisible woman named Matsuri.

Takaya Ougi is just a typical high school guy who wants nothing more than to protect his best friend and live a normal life. Enter Nobutsuna Naoe, an older man who informs Takaya that he is in fact the reincarnation of Lord Kagetora. Naoe, himself a possessor, awakens Takaya's abilities to exorcise evil spirits and fight the Fuedal Underworld. While most possessors remember their former lives before being reincarnated, Takaya does not. Naoe is thankful for this, considering his passionate and abusive past with his Lord Kagetora. As Takaya improves his abilities, he also begins to remember what Naoe did because of his love for him. Meanwhile the dark forces of the Hojo and Fuma clans begin their attack as the Fuedal Underworld descends upon the living world.

While riding with Jack Atlas and Crow Hogan, Yuusei Fudou's Stardust Dragon is captured by Paradox, a mysterious Turbo Duelist from the future, during a Turbo Duel and turned into a Sin Monster. With the help of the Crimson Dragon, Yuusei chases after Paradox as he enters a time slip, ending up in the past. During this time, Paradox duels against Jaden Yuki, who is still able to use the powers of Yubel and The Supreme King. However, by this time Paradox had also captured Cyber End Dragon and Rainbow Dragon and overwhelms Jaden. He is saved thanks to Yuusei and the Crimson Dragon. Jaden informs Yuusei of Paradox's true intentions. By stealing various monsters from across time and turning them dark, he plans to kill Maximillion Pegasus, the creator of Duel Monsters, preventing the game from being created and causing the events of all three series to never happen. Yuusei and Jaden agree to pursue Paradox, which leads them to the past and causes a meeting with the King of Games, Yuugi Mutou. However, by the time Yuusei and Jaden arrive, Paradox had already attacked his time, supposedly killing both Pegasus and Yuugi's grandpa, and had also managed to steal Blue-Eyes White Dragon and Red-Eyes Black Dragon. After explaining everything to Yuugi, he agrees to fight with Yuusei and Jaden against Paradox in the ultimate three-on-one duel to free the trapped monsters and save both the world and time itself before it's too late. (Source: Wikipedia)

Following the line of the precedent OVAs (of the same name) This anime goes around the normal lives of some elementary school (5th grade, 2nd class room) kids and their adventures, while turning to teens. Their games, stupid jokes, and the misunderstandings around their premature attraction to the opposite sex. Ryota Satou is the main character here, but his friends are almost as important as him since the school wouldn't be the same without them, especially the girls who the majority of time appear to be mature by their ages but in the ends they are as childish and even more "dangerous" than the boys. (Source: ANN, edited)