(Chronology: Daihaseisai Arc of A Certain Magical Index.) The Daihaseisai is here! A festival event where all the schools in Academy City compete with each other in sporting events.. a festival even more popular then the World Cup. Espers from all over are encouraged to use their abilities. Meanwhile, the Board of Directors have taken an interest in Ben Tennyson after his success in defeating the Eigth Level 5 Impulser.. the Level 5 whose power was impossible to categorize.. and Aleister Crowley, the City administrator has taken up a rather sinister plan to find out how to test this new weapon in his arsenal... attract the most powerful conquerer in the Galaxy to do battle with that boy. Meanwhile, Ben is starting to realize the possibility that he might have feelings for Mikoto, but is scared of what it might mean... And while Mikoto feels the same way, she doesn't know what to do with those feelings.. But of course.. all things must eventually converge and resolve, for better or for worse.

A singer in the fresh dawn of youth. The fans are roaring as she takes the stage at Sato City's Christmas Festival. Grinning widely she yells into the din. "Hello Everyone! It's great to see all of you here! I'm so glad you could make it to the last location of my first ever Tour in Japan! it's been such a journey ya know!? Well though, before I begin, I'd like to announce a dedication to the person whose inspired me ever since I was a kid. Th-this might be awkward, truth be told, I don't think he even knew I existed till recently! But I've known about him ever since he first started out on his Summer Vacation years ago!.. I watched him grow every Saturday Morning!!" The crowd looks confused but still enthralled. Who could this person be? How could they not know about the most famous Idol in Japan? Were they in the crowd? Why only every Saturday Morning as if it were some cartoon show or anime? "I dedicate this first song to you! Come up onto the stage, the greatest super hero in the whole wide world.. well my whole wide world at least! BEN 10!!" Pavarti the Celebrity exclaims as a big spotlight shines into the audience, falling upon the stunned boy who was in the middle of sipping an extra large soda, sitting next to his two friends, a Samurai and a Time Cop, both of whom look equally stunned. "Sssss.." Ben continues to sip his coke ever so slowly, his eyes round as tennis balls as the crowd continues to stare at him. "uhhh..." Ben says, holding up a nervous hand. "Hi..?" "GODDAMNIT!" roars the Time Cop. "WHY IS IT ALWAYS YOU!!!?"

ITS HERO TIME.. or is it Deja Vu Time? After a tussle with the mysterious contestant of the Radiant War known as Shi Jian, aka the Time Traveler, Ben starts to suddenly find himself reliving the same day over and over again. And what's more, Shi Jian himself is ALSO caught up in it, much to his chagrin. If the two of them wish to escape the loop, they must now work together to figure out the source of the loop, and in order to do that Ben must unlock his time traveling alien form, Clockwork. Can the two get over their differences and learn to work together? Or will they be stuck in the time loop for all eternity.. or.. er.. that moment in time.. uh.. what do I even call this!?

The Fairy, The Demon, The Star, The Vampire, The Time Traveler, The Killer, The Alien Hero. These 7 people are known in one way or another, as heroes of the Earth from which they hail. Each Earth is different. Some hail from a magical world filled with demons, dragons and monsters. Others come from a world constantly changing due to Temporal Threats. Two come from a nearly identical Earths, and one hails from a world where Japan still relies on lords and swords. Ben has no memory of who he is or where he came from. For as long as he could remember he has lived in Sato City Japan, attending Mizuki High School with his friends. However, things change when one of the students in his class, Hanzo, appears in front of him during an apparent 'date' with the school beauty Erice Tsukiyomi. Hanzo kills Ben immediately, only for Ben to awaken the next day in his own bed barely clinging to life as a strange device activates on his wrist. The Radiant Wars have begun. Now Ben has to fight to kill and rediscover his incredible powers, for there can only be one left when the blood and dust settles.

A 3rd world war seems to be looming on the horizon as somehow, the world all seems to be turning against Academy City thanks to the influence of the Roman Catholic Church. Touma Kamijou and Index are both sent to Avignon, France in order to help destroy an artifact being used by the Catholic Church to turn the world against the Science Side and cause war. However, they disappear soon upon arrival.. and Ben and Mikoto step in to search for them. Things get more difficult however when Vilgax makes a surprise visit to France.. and Ben finds himself facing another member of God's Right Seat, Terra of The Left, while Mikoto is left to fend against the mysterious Malware, a being born of Tree Diagram and the DNA of Upgrade. The world seems to be turning further upside-down as the occult, science, and what lies beyond our planet get mixed in a titanic showdown.

After being presumed dead... the chaos left in the wake of Ben Tennyson and Mikoto Misaka's absence have proved to be a little more than people expected. Now that it's protector is 'gone'.. aliens from all over as well as some of Earth's own villains have set their sights on our third rock from the sun, leaving Rex Salazar and Kuroko Shirai as well as Ben's other remaining friends with their hands full trying to fill in for Ben and Mikoto as Academy City's protectors. To make matters worse.. American Politics takes a startling turn as one of the candidates starts to move against allowing any form of alien life on Earth, making things hard for Helen and the Plumbers based in the United States. Overall it's a scramble to keep things in order after a deadly war, while everyone asks themselves the same question: Are Ben and Mikoto truly dead..? And if not.. where are they!?

A mysterious explosion has ignited in the Eurotunnel in Britain. So far, the thoughts are that France bombed the tunnel as part of their retaliation during World War 3. However, Necessarius believes differently, and has called in Index to investigate. Meanwhile, Ben, Mikoto, and company, have spent the better part of the entire year battling on the side of Academy City in various warzones, Ben further questioning all the while whether the side he picked is the right one. So far, the only reason for the war not breaking out into something worse is due to Russians fearing the power of Ben's current most powerful form: Atomix. However, Ben and Mikoto are called by Necessarius to accompany Index and Touma as an extra security measure to investigate the Eurotunnel Bombing. And along the way, Ben meets the 3 Princesses of the British Royal Family, Rimea, Villian and Carissa. Villian is currently being backed by Necessarius for the throne.. however, Carissa is intent to gain her royal birthright.. by any means necessary.

Index has been kidnapped by Fiamma of The Right to initiate his plan "Heaven on Earth" a plan conducted in partnership with the High Breed to penetrate Aleister Crowley's defenses and raze the Earth clean of life. Meanwhile, the Highbreed begin their attack on countless worlds, determined to commit complete 100 percent Genocide on the entire Universe. All that's left to fight them, is Ben Tennyson and his friends... All the fights end here.. the fate for the entire Earth hangs on these heroes' shoulders.

It's the 3rd day of the Daihaseisai, and Mikoto and Ben finally have established themselves as a dating couple. However, Ben wants this relationship to be special.. he wants to do something that will guarantee a lasting relationship with Mikoto. Ben's luck pays off when for once in Touma's life.. HIS luck actually pays off. Touma wins 4 tickets to Venice, Italy. A seaside city of romance.. and with his generosity, Touma invites Ben and Mikoto to come along with him and Index. However, romance isn't cheap.. sometimes there are unforetold detours.. like a certain magical organization that is preparing itself for war! Can the super powered alien forms of Ben 10 match up against the forces of the God's Right Seat? Or is this vacation going to be the last vacation Ben and his friends ever take?

An Invasion of Academy City has begun. The Catholic Church has sent one of it's most powerful magicians Vento of The Front, in order to begin an invasion of Academy City by the Magic Side. However, Aleister doesn't plan to let his foes take him down easily. Meanwhile, the world's most powerful Esper, Accelerator finds himself fighting his own battle. Ben Tennyson finds himself caught in the middle of these two vicious battles by a strange circumstance, unwittingly dragging Albedo into the situation as well. This collision of Academy City's greatest powerhouses and the Magic Side's intent for control, is bound to cause mass mayhem.. the Invasion of Academy City has begun!!