Our story begins like many others, with a NEET pervert getting hit by Truck-Kun. Our protagonist is then isekaied into a fantasy world, "Cruinne". Cruinne seems like a fairly generic fantasy world you would find in any Isekai video game, light novel or anime. However, the NEET pervert is a woman this time, and the fantasy world has already suffered from the apocalypse.

A Demon Lord by the name of Vanstagoth had already taken over all of Cruinne 50 years before our Hero ever got there. And in that time, the Demon Lord has cut off Cruinne from all other worlds. When beings die, their souls are either forced into the Vanstagoth's army or wander the land as lost spirits, attacking, possessing and sometimes doing far worse to the average peasant. The Vale of Souls is now only one-way. Souls can enter Cruinne but not leave it.

The Demon Lord's army occupies every major settlement, and all adventurer's guilds have been outlawed. The top adventures either joined Vanstagoth, were hunted down and executed or went into hiding, never to be seen again. To top it all off, Vanstagoth's magic has stopped any new adventure from being born into this world. But that magic only has control over the souls born into this Cruinne.

Thus our Hero, the first adventurer born in 50 years and the only living adventure who has not given in to the Vanstagoth's will, has arrived into the world. She has been given an adventurer class and told to take down Vanstagoth and his army, there is only one problem...

Our Hero is too focused on her lustful urges and see's the current state of the world as the best way to get her fuck on with all the monsters and fantasy creatures she fantasized about while playing hentai RPGs.