As it rains outside, Grandpa Max takes a nap at the end of the RV. Ben plays a video game, and Gwen stares out in the open. She tells Ben that it is boring, and she is wondering if Ben would actually let her play. There, Ben decides to let her play, but Ben is immediately annoyed by her frequent gloating about her superiority. Ben grabs the controller away from her to purposely let her lose a life. Then Ben transforms to Upgrade to reset her accumulated points, thus angering her even more. Suddenly, a lightning flash hits the Rust Bucket, and then forces both Gwen and Upgrade into the game.
Ben and Gwen are in the video game, and Ben seems to enjoy how it is going along so far. They find that they are in level one of the game, and they fight a group of what Ben refers to as Robo-sumos. Gwen decides to give it a try and she destroys a group with no problem. The matter may be bad, but the Omnitrix timing just made it worse, as Ben’s Omnitrix does not contain any of the alien forms. Even more, they are down to their final life. Ben finds an Akeni Trunk, and there two tokens. Ben decides to head out with the samurai sword. Gwen on the other hand, chooses the other icon, and reads a set of instruction before taking action. Ben is surprised by how Gwen handles the Chakram, though she states that she’s learned to handle it by reading the set of instructions. Ben does not know that there were a set of instructions that came along with it.
They head to the next level, and the platform takes them to a floating mansion. There they deal with more robot sumos, and they make an attempt to stay alive. Ben notices another trunk and he opens it up. Inside contained a Fourarms token, and he immediately transforms to Fourarms. A giant man comes to him and asks if he is a shape shifter. Fourarms identifies him as Ishiyama, and tells him that he’s his biggest fan. Ishiyama mistakes him as his archenemy, and slams the ground to bring Fourarms to his doom.
Four Arms continues his attempt to convince him that he is not Kenko. Gwen finds Fourarms in danger, and she jumps down to help. Her skills seem to take Ishyama off from the topic, thinking that Gwen is a magnificent warrior. Jealous, Four Arms decides to show off who is the better fighter. As he jumps onto a robot, he transforms back into Ben, not knowing what to do next. The only way out is for Ben to become Upgrade again, but unfortunately, he must find the icon that holds it. Gwen looks at a map and finds that Upgrade is somewhere in Level 13. Ben states that it is impossible to get there, unless there was a cheat to get through easily. Ishyama tells Ben that cheating is not a good option, though he still says that he knows his way around to get there.
Ben notices that he’s never explored such an area. In a dark hallway, a mysterious figure appears. They continue on, and Ben notices another trunk. He opens it, but Gwen acquires the bow and arrow instead. A secret room opens, and Ben heads in to pick up the tokens in what probably held the aliens. Unfortunately it was only a trap, causing Ishiyama to lose a life.
They arrive at what Ishyama refers to as the Chamber of the Kappa, and he says that it will grant them the way to the level of choice if they were able to solve its riddle. Ben notices a Cannonbolt icon, and he heads to it. A figure immediately appears and constricts Ishyama and Gwen, and he tells Ben to give him details about the Upgrade icon. Kenko sends his henchmen to deal with them. They seem to have no problem fighting them, but unfortunately, Grandpa Max is awake in the real world, and pauses the game. They call out to him before he can turn the game console off.
Grandpa Max realizes that they are in the game, though at first, he thought that he was going crazy. Grandpa Max unpauses the game, and they continue the fight with the henchmen. Cannonbolt accidentally causes another one of Ishiyama’s lives, after knocking him into the hole in the floor.
Gwen solves the riddle, realizing that a gentle vow is represented with a courteous bow. The statue transforms her into a sumo, and she uses it to smash the statue to open the Dojo to Level 13. They are taken to the Arena of Sumo Warriors, and there, they find Kenko as a lion readies to attack. Ben insists that he would fight Kenko too, but Gwen tells him that he should act like a hero by looking for Upgrade, instead of impressing a computer program. Kenko destroys both Gwen’s weapons, though Ishiyama was there in time to help her out.
Ben finally finds Upgrade, and Ben uses his sword to push him back away from the icon before he can acquire it. He readies to activate, but Kenko was about to slash him with the sword. Ishiyama comes right on time to knock him into the wall. Sadly, Ishiyama loses his life to him, and Gwen and Ben are in danger without any guardians.
Ben transforms to Upgrade, and he has no problem dealing with the evil Kenko. They were ready to go home, but Ishiyama comes to tell them good bye before they left. He wants Upgrade to bring him to the real world also, though Grandpa Max as a sumo appears out of nowhere and attacks Ishiyama. Ben tells him that he is a good guy, but Max knew that it was Kenko in disguise. Kenko grabs Gwen to use her as a threat, but Upgrade finally defeats Kenko once and for all.
Ben and Gwen get back to the real world. Max indicates that it stopped raining. He tells them that they should head out and have some fun for a while. But inside the RV, Grandpa Max only sent them out so that he would enjoy the video game to himself.