Shiroe and the other adventurers have been trapped in the world of Elder Tale for several months. They’ve now gotten used to living in this world, even gaining the trust of the NPCs. Akiba is flourishing; however, the Alliance running the show is soon to be out of funds, not to mention the fact that there are rival spies in the area. Shiroe finds it necessary to explore more of their world, so he sets out to venture beyond the bounds of the city. 

Much like Sword Art Online, Log Horizon features main characters who are trapped in a virtual world. The way in which NPCs and world events have evolved after the main characters are trapped in the game is very much like Alicization – War of Underworld given the fact that the very actions of NPCs have brought the world to a very interesting standpoint – the world of Alicization does not need human intervention. 

The once-popular online virtual reality game, Yggdrassil, is in its final hour. Momonga, a powerful wizard and master of the dark guild Ainz Ooal Gown decides to spend the final moments in the game as servers begin to shut down. However, to his surprise, he finds himself still logged into the game despite the servers being shut down and even more surprising is how he has become fully conscious as his character while non-player characters have seemingly developed personalities of their own! Stuck in this strange situation, Momonga commands his loyal servants to help him investigate and assume control of this new world in hopes of someday figuring out what happened and if there are others experiencing what he is.

Again, much like with Log Horizon and of course Sword Art Online: Alicization, the NPCs in Overlord have gained their own faculties and affect the world in their own special ways. This is over and above the fact that the two titles have the same general premise of being about characters who find themselves trapped in the world of a videogame. Overlord and Alicization also have the similarity of presenting some kind of in-world conflict borne of the actions and lore of the worlds themselves and their NPCs.

In the world of Flonyard, an alternate Earth where humans with animal ears reside, the Republic of Biscotti is a union of dog-like people which is under attack by the cat forces of the Galette Leo Knights. In an attempt to save her country, Princess Millhiore summons a champion from another world. Outbursts Izumi Cinque, a junior high schooler who agrees to save Biscotti, retrieving a sacred weapon known as the Palladion. In Flonyard, war has no casualties and instead, the warring factions participate in sports competitions to raise money for their respective countries. While Cinque performs his job as a hero well, he soon realizes that heroes are unable to return to their homeworlds. Until they can figure something out, Cinque serves Princess Millhiore and the Republic of Biscotti. 

Dog Days and Sword Art Online: Alicization – War of Underworld have the common themes of conflict or war as well as the idea of characters being forced to participate in worlds that are foreign to them. Alicization – War of Underworld is the continuation of the Alicization story and features the war that breaks out between the humans in the virtual world, and the forces of the Dark Territory that have threatened to wreak havoc on the world, which makes it somewhat similar to the Biscotti war against the Galette Leo Knights. 

The Four Cardinal Heroes are a group of ordinary guys from modern-day Japan who find themselves summoned to the Kingdom of Melromarc in order to save it from the Waves of Catastrophe. The Waves have repeatedly brought death and destruction in their wake. The heroes are each bestowed a special weapon – one wields a spear, one a sword, one a bow; however, Iwatani Naofumi is not impressed when he realizes that he has to wield a measly shield. Lacking the offensive capabilities associated with heroes, Naofumi is ridiculed by the other heroes and the citizens of Melromarc. Each hero is given resources and a party of comrades and Naofumi sets out with just one person – Myne Sophia. Things seem to be going well with Myne until she betrays him and accuses him of taking advantage of her. The entire kingdom turns its back on Naofumi and he is forced to journey on his own, with a terrible reputation following him wherever he goes. Despite his predicament, Naofumi is still a hero and does his best to protect the Kingdom of Melromarc from the Waves. 

The world of The Rising of the Shield Hero is based on a videogame, at least according to the three other heroes. Naofumi has no experience playing any game similar to the world. However, this remains a similarity between this anime and Sword Art Online, not to mention the fact that Shield Hero is all about Naofumi and the other heroes combating the waves; which is not unlike the war between the Integrity Knights of the human empire and the agents of the Dark Territory. 

When an interdimensional gate opens up in the middle of Ginza and ushers in an army of supernatural creatures and warriors from another realm, pandemonium ensues. Off-duty JSDF officer Itami Youji happens to be in the area to attend a doujin convention when he is caught in the chaos, but he remains calm and helps to save as many lives as he can as the rest of the Japanese Self-Defense Force thwarts the invasion. Months later, Itami is tasked with leading an expedition through the gate into the region beyond – now referred to as the “Special Region”. With his special recon team, Itami must travel into this unknown world to befriend locals in order to establish peaceful ties within the ruling empire. Failure would result in a war far more chaotic than the devastation that befell Ginza a few months prior.

GATE and Sword Art Online features some kind of alternate world or universe. The difference is that GATE happens in reality and the events of Sword Art Online: Alicization – War of Underworld happen in a virtual world. However, in both shows, the world alternate to reality is in many ways based on fantasy elements and features some kind of long-standing conflict that the main character finds themselves roped into at some point in the series. 

Den City is a place where duelists live and enter a virtual reality space known as Link Vrains. In Link Vrains, users can create their own avatars and participate in games of Duel Monsters against each other; however, it is threatened by the hacker organization known as The Knights of Hanoi. High schooler Fujiki Yusaku assumes the alias “Playmaker” and battles against them; however, one day, Yusaku comes into contact with a strange AI that causes a digital phenomenon known as the Data Storm, where duelists surf on the current of the wave whilst dueling in an event known as a Speed Duel. Yusaku combats The Knights of Hanoi with hopes of uncovering the truth about his own past. 

Both VRAINS and War of Underworld have events that occur in reality and in some kind of virtual world. In both shows, we are presented with some kind of conflict that happens in the virtual world, a world which has taken up a form of its own and can be considered to be existing independently of human interference. Sword Art Online and VRAINS also have a similarity in how they place the element's main character’s past with experiences that they have had with the virtual reality itself.