"Hai to Gensou no Grimgal" draws its inspiration from classic J-RPGs such as Dragon Quest, Final Fantasy, Romancing Saga, Suikoden, Star Ocean, Xenogears, and many others. Those who are familiar with RPGs coming out of Japan when the Playstation 2 was the king of videogame consoles will immediately find themselves on familiar footing.
That being said, recently there has been a rise in popularity of series such as Sword Art Online, which also takes place in a world patterned on MMO RPGs. Series such as SAO are defined by characters who are genius fighters and can cut down anyone in their way without much preparation or training.
Grimgal purposely seeks to rebuff this idea by introducing characters who must, quite literally, earn their way in the world. Following the development of these characters; their laughter and tears, triumphs and defeats, and perhaps most importantly, their relationship with one another other, is a major aspect of the story.
Survival in MMOs is a funny thing. It doesn't matter how badly you want it, or how hard you try, it can't be done alone. Especially when the MMO is Sword Art Online. The virtual reality video game in which if you die in game, you die in real life too. It doesn't help either when the most dangerous band of player killers want you dead. It'll be hard enough to survive, but retaining sanity is another task entirely...