Warning: This Section Contains Spoilers
1. Escape From Reality
In the anime, Kirito escapes reality by logging in to a full dive VR game called Sword Art Online. As the story progresses, he tries to make it back into the real world, while also saving his friends in the process. However, in the “real world” they don’t have too much going for them, and the relationships they form will last forever. Later on, Kirito visits many other virtual worlds and he feels the most at home in one of them.
When virtual reality offers more possibilities than true reality, why wouldn’t you try it? Obviously, SAO isn’t isekai because they are in a game and can make it back. But, it still offers a peek into a whole lot of new worlds, filled with interesting new people and adventures. The change from the boring ordinary is what both SAO and isekai do very well, which is what makes both so appealing.
2. Loveable Romantic Interest
When you’re home a lot, you don’t get to meet a lot of people of the opposite sex. And usually, the main characters in isekai are shut-ins, overworked busy people, or just not very social. Kirito is also one of them – he spends most of his time playing games, and he is very good at them. So naturally, when he gets stuck in SAO and meets Asuna, he is immediately smitten. The readers and viewers enjoyed watching their relationship develop, as it was something that gave a special meaning to the storyline. It was also quite refreshing to see the main characters pursue an actual relationship.
This aspect is present in Arifureta, Outbreak Company, and Philosopher’s Grandson. Re:Zero is another good example, where the main character pursues one love interest while ignoring the rest.
As we mentioned above, it’s hard to meet people when you’re a loner. So naturally, when the main character gets isekai’d they meet a lot of new people and make friends. But some of them also see the MC as a love interest. In SAO’s case, it’s a mix between both. While his female friends show him affection and in some cases have romantic feelings, they also accept that he only has eyes for Asuna. They keep treating Kirito as a friend, while also trying to protect and support him.
Harems in anime are nothing new, as it’s an old trope that survived the test of time. However, with isekai, it truly gets to shine as the main character is living out a fantasy that wouldn’t be possible in the real life. More recent shows that have them include In Another World With My Smartphone, Death March, Mushoku Tensei, and more. My Next Life as a Villainess is a great example of a reverse-isekai (with female MC), which is less common but still present in anime.