The Character I Leveled Up is Naked?! Ropuremon's School Dungeon!

All machines become RPGs.

Summary
After accidentally appfusing and  together, Haru beholds the newly emergent. DoGatchmon easily blocks Cameramon's attack before retaliating, causing him to flee. DoGatchmon reverts, leaving Gatchmon and Navimon exhausted, while Haru obtains DoGatchmon's now dormant chip.

On October 15 at Fujimizaka Middle School, Haru discusses DoGatchmon with Gatchmon and Navimon while the latter two argue. Gatchmon explains the differences between Applink and App Fusion: Applink is the general case where two Appmon combine their strength, while App Fusion is the rare case where the pair combine and digivolve to a new level. Navimon then swears loyalty to Haru, which causes Gatchmon to defend his place as Haru's Buddy and leads to another argument. Gatchmon also explains that it will be a while before DoGatchmon can be appliarised. Their conversation is interrupted by Yuujin, who finished soccer practice and was looking for Haru. The two of them head to Kashinoki Books, where they discover Waston,, and discussing Fantasy Saga and Watson's achievements in it. They end up discussing it and its popularity along with Ai, but when Haru asks Watson to see his equipment, his character, despite known to be high-ranking, is show to be at level 1 with no equipment. The others realize their own characters have suffered the same fate, which is when Haru sees emerge. Ropuremon leaves, but Haru gives chase.

Across the city, digital displays begin being modified to represent typical role-playing game quests while phone and internet services have been disrupted. Haru chases Ropuremon to an AR-Field centered at his school, which has been modified to represent the Amusing! Exciting Dungeon game. The game was an RPG released three years ago with a high initial install base that quickly plummeted due to its relentlessly hard early levels and ended service after three months. A monster attacks them but proves to be extremely strong and resistant. Haru uses a search to find a guide site, which explains the complicated method of beating it. A trap-filled trek through the dungeon ensures, with Gatchmon falling victim and Haru being enthusiastic over every event.

Finally reaching the end, they find Ropuremon, sad and despondent that they reached him so easily. Ropuremon get angry at them using a site rather than exploring the world, but Gatchmon counters that the game is impossible without a guide and reinforces it with comments from the forum. That the game is boring especially hits Ropuremon hard. He flashes back to his 3rd year RPG class, where the Ropuremon attached to the Fantasy Saga game is receiving recognition for his success while pitying other games, especially his own ''Amusing! Exciting Dungeon''. Ropuremon was depressed and eventually infected with the L-Virus. Now angered, Ropuremon achieves a gigantic size, which Haru attempts to counter with App Fusion. Unfortunately, the App Fusion fails, creating the ineffectual. Sukasimon is easily defeated and reverted, after which Gatchmon and Navimon get into an argument that Haru believes the root of why the App Fusion failed. Ropuremon moves to attack Gatchmon, but Haru stops him when he counters that he didn't find the game boring at all. He admits that it may be because he loves fantasy novels, but he likes everything that happened during the dungeon crawl and is sure that others found it fun too. Haru telling Ropuremon this is enough to pacify him, and Ropuremon purifies himself, revealing that he also is a 7code Appmon as well.

Gatchmon reveals that 7code Appmon are seven Appmon who each have a piece of a special code. He believes that, with all seven, they can face Leviathan. Haru also obtains an Appmon 7code PAD which can store the power of the 7codes. They decide to make it their goal to obtain all of the 7codes. Purifying Ropuremon fixes the problems in Tokyo, and everyone's Fantasy Saga accounts return to normal. In another AR-Field, Rei Katsura and obtain, who is another 7code Appmon. Hackmon tells Rei that Haru has obtained a 7code Appmon, and Rei states that he will not let Haru reach Leviathan.